Everywhere in the Alps has view from great to unbelievable 🙂 What does she want from lakes, look at them or swim / boat on them ?
Lift asisted in Switzerland – best known is Verbier but not easy to get to Lakes (Lac de Vaux is quite a hike in the summer) and Lake Geneva/Montreux is an hour. Lakes in Lenzerheide itself – possibly best bet for the combination you are looking for – family mountain railway ride to Arosa for the day and you go “over the top” and bike back ? Zermatt is just wow but very pricey, 2-3hrs from Verbier for a day trip
Lake Garda is a fantastic playground full stop. We normally stay in Malcecezine for sailing and the cable car runs from there, numerous uplift options by van also (from Torbole)
You could considsr Annecy area and ride Semnozand/or La Clusaz. 1 hour to Chamonix and/or Samoens