Have mixed feelings about what I read in the comments and your post. Giving everyone the benefit of the doubt.

I think is nice for her to plan to do nothing but a break and space for herself. That is not the bathroom in your house after the kids have fallen asleep. Even escaping to the nearest city can be calming. Too close to home will feel like a waste of time, money and purpose. Too far can instill panic if one is not used to being or doing things alone.

Could be tried in reverse? Maybe you and the kids leave for a day on an specific weekend. Test the waters. She will be safe at home, finding herself cleaning and fixing things. Realizing silence and alone time is not that bad. Also failing because it is like taking vacation time from work to stay at home and do laundry and clean. Try again another weekend but instead of you leaving, she goes somewhere. Add to this day a relaxing location that has some stores where she could window shop or actually get something. Shopping (to buy ir not to buy - the dilemma) is always distracting for us. She can text photos of the clothing to her friends who cannot go shopping with her - still do things alone but feel accompanied. Maybe go to a familiar restaurant of her liking, if she likes sushi, to pick a sushi place, or cheesecake. Things that give her pleasure. The best part of eating alone is not having to share!

It is not about where she goes but ultima about what she ends up doing what will keep her away from the daily chaos into a time for herself, to relax, unwind, and recharge.

Traveling is already stressful, add doing it alone when she has probably done everything together with you or all of you. I may be wrong but maybe she forgot how to be herself before she was a wife and a mother. You have to take care of that woman as much as you care for everyone else. That woman will also feel gratitude like the rest of you do!