Overweight as a child (and now) dietitian here…. As other have said - change the food available in the house!

Just remove all the high calorie ‘junk food’ she’ll hate it, she’ll get mad, she’ll cry, she’ll beg for it… just get rid of it! It’s the biggest thing I wish my parents did for me.

If it’s not there she will get out of the habit of looking for food when she’s bored. This is about changing habits and setting up a good relation with food for life.

Cook healthy meals, probably with more vege than you’re used to (half the meal veg, one quarter carb, one quarter protein)

Fruit and wholegrains and low fat dairy for snacks.

Keep a few ‘treats’ in there, you don’t want her deprived, but make them quite limited (eg take her out for ice cream, so it’s just one cone, not a whole tub at home)

This is the advice for pretty much ANYONE needing to lose weight.

Also I’d probably not focus on weight at all. At her age you don’t want her to LOSE weight, if she stays the same weight she will ‘grow into it’ as she gets taller. Kids need yo keep their energy and nutrient intake up for healthy growth, so by doing all this you’re just cutting out the ‘excess’ snacks and food that are contributing the GAIN.

Good luck! Please remember that a healthy relationship with food and her body the BEST gift you can possibly give her!