Actually, there are numerous bee species that will nest solitarily in the soil. Only a good picture could help us ID the insect you've seen. I would consider this a good thing, and not automatically jump to the conclusion that she is looking for trouble!

I had some insects that look very much like honey bees last year, but they turned out to be bee flies, and I don't know how or where they nest. There's also a ground nesting bee that looks like a small honeybee that I see from time to time. I've never noticed any agression from them. If I can manage to get a photo, I'll post it and you can look to see if it's the same insect.
Mrs H.

THanks that would help.