I was the one posted about if I should gift my sister.

I forgot to add that she told mum to have me gift her at least $1000 since she has a baby and need help put down payment of the house. I am a well established young professional and she doesn’t work, my mum asked me why can’t you help my own sister? She has nothing but I have everything.

Am I being selfish not to give her a dime for her wedding though I have more money than she is?