My child needs to lose weight advice and opinions

My 5 year old has gotten to an age where she is no longer in that cute toddler body where chub is just the way they are build.

She has a kids body she, she is a little chubby right now (and I know kids go through that phase) but I’ve seen family members with kids who it started at this age and now they have 130 pound 10 year olds.

I do keto and I’ve read it can give kids other benefits besides weight loss, she’s always getting sick so I also need her to be eating a healthier diet (my mom buys her junk because she’s to lazy to shop for food while she is there and if I bring food it ends up getting eaten by my younger siblings that live with her) I also really want to get her into a sport I think she is old enough to start that.

I don’t feel crazy that I want to do this but a lot of people look at me insane when I say I want her to do keto with me.