My BMs and my FMIL just hosted my surprise bridal shower (and two other  people helped them out a lot). Am I supposed to give them a gift more  than just a heartfelt thank you card? I sort of thought that the gifts  you give them later covered the work they put into the bridal shower. I  know that those extra two people aren't in the WP, but I thought that if  it was okay, a thank you card to each of them would be okay. 
Any input is greatly appreciated!