Thread: 223 55gn sp options and performance advice please

As most of you know I'm pretty happy shooting most things with the 300 wiz bang however little miss just turned 12 is keen to shoot a deer and through some good mates it appears I may have the opportunity to get her within 100y of a fallow in the not too distant future.....now I know the 223 can be a very effective deer caliber and even I shot my first deer (a fallow doe) at 200y with dirt cheap 55gn belmont ammo......
So question is currently I have a howa mini and it shoots fantastic with fiocchi 55gn sp factory ammo but it's a fair whack slower than the box speed dictates ( granted 20" barrel and all) but 2886fps chrono and range varified.
For the experts @Tahr springs to mind will this be acceptable for a fallow at inside 200y and hopefully 100y or less (engine room shot) ? I have a 1:8 twist but zero interest in loading for the 223 at this stage.
I was looking at Sako 55gn game heads sp quoted box velocity of 3166fps as another option was also open to heavier factory loads but have heard varing reports that a lot of heavier factory loads are a bit hard up close and can pass through doing minimal damage if shot placement is not ideal.
Let's be clear miss 12 can shoot consistently at a 200y 6" gong and is being schooled up on shot placement but I just want to try and use the most effective round possible to hopefully give the best result and make this a good experience for my daughter.
Please no use a bigger caliber comments she will be using the 223 as that's what we have and it's a great accurate shooter thst she is comfortable with.
Looking forward to your thoughts guys

Ps: the 300wsm is just a bit too much of a step up from the 223 she is confident with.....don't want to scare her off Centerfire.