We do this! Our rental is on the second floor of our house...separate entrance and everything.
We have 4 very young kids and a dog! It is disclosed in the description like this, "We live on site, so if you need assistance we are always in and out. We will do our best to make your stay more awesome!
Our four preschoolers live with us. They are not always quiet, but they are always adorable! :) You can expect quiet on school days from 8-2, and at bedtime from 8 pm to 7 am."
The first part, about us being on-site, turns a negative into a positive...you're right there to help if they need anything! Not every airbnb is like that.
We've been renting for a year and a half now. We had one bad experience, a 3 day stay that wanted to leave early and wanted a refund on her last day. I said no, because I felt that the noise was disclosed in the description. She left a critical review, not nasty, but critical. In hindsight, I should've just given her the refund.
However guests that stayed after her left very nice reviews, even defending us against her review, by saying "the kids were so cute, we loved watching them play and laugh, and the noise wasn't a problem and was disclosed in the description", so that was nice.
We do provide a bowl-full of earplugs with a cute poster that says "Help yourself we want you to get a good night's sleep".
We also keep our price a bit lower than the competition. Too low, and no one will book because they'll think it's a dump. Too high though, and you get picky clients. In the beginning, err on the side of too-low because then you'll get great reviews when people are impressed by the space.
I think you'll do just fine! Good luck!