My 17 yo daughter now uses a Mark V ULW in 280 Rem. She used a 243 howa for years and killed lots of deer with it. The AR platform :-) Personally I love Weatherbys and AR's. The same daughter also shoots a ton of 204 Ruger thru her AR built for coyotes and rock chucks. I bought a super nice AR several years ago and I think I now have about 9 different uppers I can use on my original lower. If I had to start over again with a little one I would build her a AR in 6.5 Grendel for deer hunting and all around shooting. In the AR platform with a linear comp the kick is negligible I would build it light and the adjustability built into the AR makes it a rifle for her whole life. 300 Blackout I have two uppers in that and have used it quite a bit on deer inside 100yds. Definitely not the same result as the Grendel.

Just my 2 cents

Have a great day