The other option you forgot to mention: she may see herself as a friend who is helping somebody in need. I recall my ex having many "friends" that thought they were "helping" the poor thing. Two of them almost died before I figured out what path I was going to take. Once I did, it no longer mattered who her friends were.
I mention that mostly because things aren't what they seem with your H. Opposites. Upside down. Backwards and forward. Tumble, rinse, repeat.
I wouldn't let her in either. But more because I didn't know her. And because if your H needs to get something done, let him do it himself. Not out of spite, but out of respect for his wishes to do things on his own.
In the end, you only really know what you know. Everything else is conjecture that will cause you drama and anxiety. Try not to go there - it'll make you crazy...
Make sense?
AJ
"Our lives begin to end the day we become silent about things that matter" MLK Put the glass down... "Yesterday I was clever so I wanted to change the world Today I am wise, so I am changing myself."