how often should you speak to a relative?

[L R]

Actually I think you should talk to her as much as you like! Especially if you just met her, you probably have a lot of catching up to do

I really think older generations appreciate it when younger generations show interest in getting to know them. I have quite a few aunts/uncles and they always appreciate it when I send holiday cards or just phone them to chat.

Even if conversations tend to run long, you could always say "if you have to go, don't let me hold you conversation hostage" etc.

Family is a really important part of life, and I hardly think you could impose on your great aunt by IMing her frequently. Just don't start asking her for money lol.