Can anyone help me with words?

My baby was born end of Oct but my best friend has been TTC now for 3 years and since my baby has arrived she has really struggled. I feel terrible especially when I managed to fall quickly.

I’m treating her to a spa day tomorrow and made her up a goody bag.

I’m so bad with words and want to write a nice message in her card. She has a 7 year old son, as do I. And they are best friends too. I think we always though our 2nd child would grow up friends. What do I say?? Xx