I assume you're referring to the reconstruction of a woman with a battle wound?

The problem with this kind of story is that so many people are so desperate for there to be real Viking Warrior Women that they're seeing Viking Warrior Women whether they existed or not. For a variety of reasons, people find the idea of Valkyries and Shieldmaidens inspiring or enchanting, but we have to be very careful about putting too much faith in anything that suggests they were a common phenomenon.

There is some textual evidence that some Scandinavian women did fight, but we can't take this as evidence that there were Warrior women in the pop-cultural sense of the word, and that's also the problem with this latest find. The majority of textual evidence for 'Shieldmaidens' comes from sagas, making them inherently mythological, but there are some other sources: the Byzantine historian John Skylitzes remarks that there were women found among the Bulgarian dead at the Siege of Dorostolon, while Saxo Grammaticus remarks that there were female defenders at the 8th Century Battle of Brávellir. Grammaticus is, of course, writing some 400 years after the events and may well be basing his accounts entirely on sagas, so we have to take him with a pinch of salt big enough to give you a stroke. The notable thing in both situations is the defensive contexts in which the purported women are found: both sources have their 'warrior women's fighting as the last line of defence for besieged towns. Attacks on 'civilians', massacres, abductions and sexual assault were common phenomena in early medieval warfare; it's hardly inconceivable that women in these situations would want to defend themselves. The notable feature of this Norwegian burial is precisely that: she was found in Norway with a wound that could easily have been sustained in a massacre or attack, or simply trying to defend a home. This is a far departure from pop-cultural depiction of Viking 'warrior women' embarking on raids and voyages: had the body been found in central Wessex then things might be different.

The absence of female fighters in 'Viking' contexts or in Danish armies of conquest in the 8th, 9th or 10th centuries is worth noting. Given their polemical interest in 'othering' the Danes as much as possible, neither the Anglo-Saxon Chronicle nor Asser make any reference to there being any women among the invaders, which would surely be remarkable. Neither does Ibn Fadlan remark on there being warrior women among the Rus in his Risala, noting that, while the women carry small knives, they do not go armed as the men do.

There's a wider problem in the interpretation of grave goods and the extrapolation of a wider cultural context from individual finds: the presence of spears in graves has been used at times to argue for the existence of 'warrior women' but spears are widely symbolic of 'free' status. Similarly swords may be symbolic of wealth and status, and bows of in interest in hunting. A recent find used the presence of a chess set to argue that the deceased had been a military leader, but it could just more easily mean that the deceased was wealthy enough to have time to game, was learned, or simply really liked chess.

In this particular case, the presence of armour and a shield do provide some tantalising evidence. We can't rule out that they're familial rather than personal, but we'll give them the benefit of the doubt and say that this was indeed a lady who fought and died in the defence of a settlement, maybe even in a leadership role. The problem is that this would make her one remarkable woman, and not necessarily the exemplar of a whole caste of Scandinavian female warriors as popular culture would like to portray.

The recent finding is the first proof of a Scandinavian woman of the Viking Age who died of a severe head injury consistent with a weapon wound. Up until this point, it was conjecture that they ever really fought.

Being buried with arms and armor could easily be a ceremonial rite of sending you off with family (read: men's) goods. Metalworking was time consuming and expensive, and they made fine grave goods. Even if these women were warriors, there is no evidence to suggest that this was 'normal', and one shouldn't assume an equitable representation of gender within regular armed groups.

Most other written evidence, especially those pieces detailing shieldmaidens, are generally within the context of legend and folklore, and therefore doesn't constitute hard proof any more than Herodotus' headless men.

tldr - She died of a weapon injury to the head. This is a first, as it gives proof of a battle wound and therefore that she probably died in battle.