Margaret’s relationship with Henry VIII makes more sense with context, so I’ll start back a bit.

Arthur and Margaret were the elder siblings to Henry and Mary, and Arthur was separated as the crown prince in a way the other siblings weren’t. However Henry and Mary were closer in age and prospect at that time, and Margaret who was groomed to be a Queen Consort via Elizabeth of York and Margaret Beaufort grew to spend less time in their company. When she married James IV via proxy she became titled as the Queen of Scotland, and for the rest of her time in England it meant that Henry VIII had the lesser status and had to be deferential to her which infuriated him. Arthur died before she left, as did her mother very shortly before her move to Scotland. James IV was roughly sixteen years older than Margaret who was just shy of fourteen years old when she came to his court.

Contrary to fictional portrayals, James IV was thirty years old and a more than competent king. He was intelligent, cultured, fit, and had a mind towards increasing Scotland’s prestige. James was thoughtful and attentive to his young queen, and never spared to provide for her comfort or care. Margaret’s age meant that James could raise her up to be the sort of Queen Consort he felt was best for Scotland, and indeed he trusted her to be Regent if anything should happen to him. For her part, Margaret had lost her mother and older brother, she had been taken from her home, she was made to be a wife and consort at was still a young age regardless of the perception of the day. Her father died several years later and Henry VIII wasn’t making her life easier. James was very naturally someone for Margaret to lean on and trust, and while we can’t say if they were in love, they had a successful and affectionate marriage.

Henry VIII for his part denied Margaret inheritance that was set out to her in Henry VII's and Arthur’s wills respectively, which infuriated James and Margaret. Henry was eager to war with France, and Scotland via a treaty known as the Auld Alliance was arguably honor-bound to side with France against England. James also didn’t quite trust Henry not to try to take liberties with Scotland and was concerned with what might happen should he die prematurely.

On the other hand, Margaret was Henry VIII’s heir apparent while he was childless which would make Margaret Queen Regnant of England. As would become an issue later in Mary I’s reign, there wasn’t a statute set for how to deal with the marriage of a regnant queen, and it was a concern that James would become King of England by default. Henry wasn’t a man who liked to share what ‘was his’, and it’s reasonable to conclude that on a personal level the idea of dying without an heir and having Margaret and James by extension take over was intolerable to him. Even when Mary was born, it only put Margaret second in line, and given the preference for a male to be the heir the future sons of Margaret could make a claim to the English throne. The fact that she could, and that James could conceivably wage war [with or without France] to claim the English throne was not acceptable for Henry.

Henry knew when he went off to fight France that James might make trouble and left the regency in the capable hands of his wife Queen Katherine and left the Earl of Surrey to aid her. James reached the decision to fight England, much against Margaret’s wishes, and ended up dead along with a great number of Scottish nobility.

Dr. Linda Porter in an interview with Natalie Grueninger mentioned a letter from Katherine to Margaret where Katherine offered to send a friar from England to pray with Margaret and Dr. Porter felt the letter was a bit patronizing. Katherine had been pleased at James’ death and felt he’d gotten what he deserved. I haven’t seen that letter and can’t offer an interpretation, but Dr. Porter is a historian who has authored a number of Tudor biographies and her opinion seems well researched.

Scotland wasn’t the rogue’s gallery of crass upstarts that fiction has also portrayed, but it is accurate that the majority of Scottish nobility wasn’t pleased with a female ruler. Let alone one whose brother had [vicariously] massacred their king and a chunk of their nobles. If Margaret hadn’t married Archibald Douglas, it’s still a toss-up whether or not the Duke of Albany would have still been sent for to wrest power from her.

Either way, she married Douglas and things went downhill from there. Henry VIII had initially wanted Margaret to come to England with both her sons which could essentially put power in Henry’s hands but settled for receiving Margaret with respect. The next portion of her history is a lot of back and forth with Henry VIII, Douglas, Albany, Margaret, and various Scottish nobility. The short notable points are that one of Margaret’s sons died in Albany’s care which made him look like a rather Richard III figure and hurt his reputation. Douglas made an arse of himself but did have a reasonable amount of power and ingratiated himself with Henry who would end up siding with Douglas and [laughably] take a moral high ground against Margaret for daring to want to divorce Douglas. Henry sheltered Douglas and eventually sent him back to Scotland wanting Margaret to just bend over and accept his will. Douglas was a foil to the French-loyal Duke of Albany, and loyal to Henry who was willing to take up his cause to have a power player in Scotland in his back pocket. Margaret took another husband who ended up being a poor choice, and through all of it Douglas had essentially stolen the income due to her from her dower lands which left her in a lurch. She did end up pleading with Henry, who still never gave her inheritances she was due, and while he did give her money and goods at times he was relatively stingy and high-handed about it. When her son came more into power she still never regained great footing financially or power-wise, and he was not fond of Douglas or Henry VIII.

Margaret, much like her granddaughter Mary Stuart, experienced a very different set of problems from Mary I and Elizabeth I. When people wanted to rebel against Mary and Elizabeth, they did it with plots and rebellions. When people rebelled against Margaret and Mary Stuart, they tried to take physical possession of their person or their children in a way that was very counter to giving a ‘divine monarch’ their due respect. Margaret takes a lot of flack for her marital choices and the notion she was just willy nilly having lovers and flights of fancy. She didn’t really have a choice though, she needed the backing and support of a strong partner and for whatever other reasons she chose rather poorly.

That all being said, Katherine and Henry weren’t individually very close to Margaret. Although Katherine and Margaret experienced similar situations at points, they were never very close and Katherine had ultimately had a hand in gladly widowing Margaret. Henry willfully denied Margaret what was hers by right, and then was tight-fisted in helping her despite readily and hypocritically helping her enemies and lecturing her about morality. Certainly Margaret wasn’t pleased, and it’s reasonable to conclude there was resentment towards them. We don’t know that for sure though, while Margaret was a huge letter writer many of her letters were lost. Whether she wanted to or not she had to plead with Henry VIII for help as he was her most powerful ‘ally’, little that he ended up being one. Even if she secretly hated him, she couldn’t have said so or behaved that way. She was a Tudor and well-familiar with kingdom politics and aware of her own inconsistent position. Margaret had to play the beggar to Henry even though it should have been her place to demand her due.

Margaret made good and bad decisions in attempts to survive and maintain her position, but she had been considered by James to be a good and reliable queen consort and she did have some loyalty among the Scottish nobility. Henry VIII had a lot more to do with her ‘fall’ in some ways than Margaret ever did herself.