What is the appropriate amount of money to spend on a baby shower gift for a niece?

Hi Fellow FOF gurus – I have been invited to an engagement party for a friend (second marriage). I am still confused by the gift protocol I’ve read about so what say you? thanks cwb

Help! My daughter is graduating. I want to get her something nice but since I lost my job the budget is tight. My brother is getting her a used truck and I need to top that one. What do I do?