One thing you could do is use "Advanced Search" (link is next to the normal search field for games) and then set "Minimum Age" to whatever the youngest child's age is, and set "Filter by Collection" to "Owned" and put your user name in "Specify User". It's not the same view as "my collection", but might still help you find a suitable game.
The age range is rarely spot on, in my opinion. The community recommended age is better but these are probably mostly gamer's kids. You really need to know the kids you're playing with and the level they can handle. My 10-year old girl has been playing well above the recommended age range for years now but that's because she grew up playing games that were more than just roll and move. She loves to scoff at games that she loves that say 14+. I may be raising a game snob...IDK.