Activity for Nova

Hello! I was speaking with our officiant and with him being my FH's maternal grandpa he wanted to know more about how the processional will go. I've got it nearly finished (even with the blended grandparents and his parents), but I've hit a road...

My fiance and I are putting together a wedding on a tight budget but many venues ask you to use catering services. Is it bad to ask your guest to pay for a portion of their plate cost? It would help a lot but I would feel terrible? Please help