L.R.
I can see how this would be a hard decision to make.
How are Grandma & Grandpa? Are they able to handle your daughter for a week? I would leave my baby (and I have for three nights, 4 days with G&G for pure fun) if you know they are capable of handling your little one. And will they be staying at your house. Which I think will make it a lot easier.
Could G&G go with you and stay at a hotel close by and be babysitters on your trip?
What if they came down halfway thru the week to cut down on the cost? That way you and your husband can have alone time and family time.
Taking a 3 month old to Florida just doesn’t sound like much fun. And not very relaxing for anyone!
I don’t think you will be a bad mother for leaving your daughter with G&G – no bond will be lost in that one week.
I know my mother-in-law would love to have my daughter for a week. I think she'd move in if we let her!
Plus how nice for them to spend time with her - their first and only granddaughter. That will be a nice bond for them.
Good luck!