JMHO ,But if she is not that familier with weaapons , give her a big 'ol can of wasp and hornet spray.Hell put one in every room .it is not but abouit 4 bucks will shoot about 25 or 30 feet ,And if the attacker gets hit in the eyes they WILL go to the hospital or go blind .Plus it's alot cheaper than bear spray.Squirt then run like hell.Call the 'po'po.If you have to have a gun then 870 pump in 20 or 12 (if she can handle it,18 1/2" barrell ,loaded with 2 3/4 #4's.I have some rounds for my 870 that have a slug and 6 #1's but still use #4 buck.