if reliability is the only factor, the only choice is a revolver:
proof-
you and i are in a gun battle at point blank. we both fire at exactly the same time, and miraculously we both fail to discharge. you have a semi-auto, you have to reach your other hand up, rechamber a new round, bring the gun back up, aim, fire.
i had a revolver, all i had to do was shoot again, the carriage turns, loads a new round and shoots it.
REVOLVERS DONT JAM!
they can be harder to get acustom to, as the trigger pull is usually very hard initially, then at the end of the pull, release easily, it takes practice to learn to pull the trigger halfway, aim, then finish pulling. if it has a short barrel, it is harder to shoot accurately.
that being said, i LOVE my Glock 17 fullsize 9mm, so does my girl. smaller weapons may seem easier to handle, but more barrel/upper receiver mass equals less recoil. get her the biggest thing she is comfortable with. watch out for "slide bite" on any semi-auto that does not have a beaver tail, that can be discouraging to a new shooter.
.40 smith and wesson is the most effective round with managable recoil, but a good bit more recoil than a 9mm.
springfield XD series is a nice line, the 1911's are a classic, the shotty is best, and if you research your local laws governing the matter it may be legal to manufacture your own "sawed off". here in florida you can.hehehe.
my next $0.02, AVOID HI-POINT AT ALL COSTS! i know 3 people who have them and none of them function properly. they are dirt cheap for a reason, go with a brand name.
you have to watch for ammo to come in stock, ever since obama was elected.sign up to email lists, use the "in stock notifications", stockpile while you can before the serial number on projectiles thing is passed, and prices skyrocket even further.
gungenie.com
topglock.com, gunsatcost.com, etc, all owned by the same guy, tgscom
cabelas.com
midwayusa.com
ammoman.com
gunbroker.com
TEACH YOUR KIDS SAFETY, GO TO THE RANGE AND PRACTICE OFTEN, GET YOUR CONCEALED WEAPONS PERMIT WHILE YOU CAN, VOTE.
if you dont know your rights, then you have none. that was told to me by a LEO.
support your local law enforcement.