I wouldn't say anything to your daughter. She must decide when to do it for herself and if she goes for it . Help her to the hilt. I 'm doing this WOE with my mom. I started first and she started just to give me support. Though she needs to lose weight as well. Though not nearly as much as me. She is ten times better at it, has horrible dietary restrctions which eliminates too many foods. But she only has had one cheat in the last six months. I am no angel.
We don't live together so, the only thing she can do is give me tons of support (which I love her for) When I'm around her I eat what she eats. There are no varying types of food in the house At mine other than one loaf of bread and one box of pasta for my husband everything else is lowcarb friendly .
I would simply eliminate most of the tempts in the house, besides it won't eventually do much for your motivation to have them there. My husband has to have his potato chips and cookies away from the house. He does it cause he's supporting me in this.
Hope I didn't sound preachy. Anyway welcome to the site and good luck.