Ugh, friend wants to come and visit

Mini • First baby for hubby and I...due October 19, 2015

I have 21 days left, and the daughter of a family friend who is living in a city nearby wants to come and visit. I am 37, hubby is 42, she is 24, so we don't always have lots in common. My dad and her dad have been friends for over 30 years, so I think of her as a little cousin.

She messaged me today asking how things were going, and saying she wants to come and visit, either now to help out, or right after the baby comes.

My MIL will be visiting when the baby is born, and we won't have any more room for anyone else. I don't want anyone else coming to stay, as it'll be too much work, and frankly, I want just our immediate families around (my family lives in our city, so they can come and go, and won't be expecting to spend the night, or be treated like guests while they are here). I expect my MIL will be a big help.

How do I respond and say please don't come foe awhile? I feel that sounds very mean...but I want my last few weeks pre-baby to be relaxing, and I want to prepare with just hubby and my mom.