Welcome to the Forum!
Sixshot is absolutely correct. The 45 Colt is certainly enough gun to take down whitetail deer in your area. However,,, since you are working towards getting your wife or daughter in the stand,, I too would suggest a milder shooting rifle as their first deer gun. It's easier & more accurate at longer ranges to shoot,, and in a caliber such as a 243, 7mm-08, or 308 it's PLENTY for deer.
But if they must have the 45 Colt,, then a 200 grn cast lead bullet in that velocity range WILL get the job done,,, IF & only IF the bullet placement is correct. As sixshot says,, don't expect "edge" hits to anchor a deer.
Just yesterday I was out at my range with a few of my centerfire revolvers. I had 2 of my 45 Colts, a 44 Spl, & a 44 mag. With a rest at 100 yds,, I was keeping all my shots in 6-8" groups on different types of targets. I checked a few loads at 25 yds,, and one of my 44 mag loads shot a 1-1/2" group a few times. Then at 100 yds,, it was hitting plastic soda bottles almost every time I settled the sights correctly for the range. If I missed, it was usually either a little low,, or just to one side or the other. Still,, very accurate at 100 yds. My 45 Colt Bisley was chewing up a clump of grass at 100 as well. My spotter was commenting on how easy I made it look.