Hmm, a tired pup is a good pup - any way to get her more exercise during the times when you are home, so she doesn't have the energy to escape when you're at work? Is your little boy big enough to play fetch with her? (If she likes to play fetch - our Gracie never did "get" fetch.) I know he's probably too little to take her for long walks every day by himself ...

If she's a digger, you may end up having to fill along the fence with concrete or something else "undiggable" ...

Many boxer folk I know use a harness instead of a collar - much harder for them to slip out of.

How old is Daisy these days? Any new pictures?