The Queen of Hearts knew that the Mad Hatter was busy—preparing hats for the Kingdom of Clover, thus it was with this intention that she decided to have tea with his two friends instead. They would end up as friends of Alice in the future, not as close with her as Nicholas, but it made sense that she needed to befriend them as well.
Bits and pieces, she started to unravel the picture on her own.
Rosalyn Lockhart had no complete memory of the past, but those information that she knew, those that she could recall, she used them to the best of her capacity. And it was for this reason that the Queen of Hearts made time to clear out her schedule and entertain them, even if she had to do it with Blyke Edelweiss beside her.