From what I can gather, and I may be wrong, no they didn’t meet in person afterwards. However, it would seem that they both had a bitter admiration for the other during their rivalry. In a letter to Frederick, the Prussian ambassador wrote: “She detests Your Majesty, but acknowledges your ability...”. She also referred to him as “that evil man”. In another letter from Frederick to the ambassador he writes: “That woman’s achievements are that of a great man” which for the 18th century is a huge compliment considering she was never meant to rule.

There’s a really interesting blogpost on their relationship here: http://interestingworldhistory.blogspot.com/2013/03/maria-theresa-and-frederick-great.html?m=1