I agree with 1816's but since your wife hasnt been practicing with this set up, at least not much, I would be hesitant to start loading her up with 175 +grains up front. Her power stroke with a 25" draw is pretty short and even a tiny difference in her anchor point is going to make a BIG difference on impact beyond 15 yards, especially a shooting a K Mag which already a challenging bow to shoot accurately. Also, a very heavy arrow is going to drop a lot between 15 and 25 yards coming out of a 41# bow. Sharp arrows and shot placement are more important than penetration, imo. She'll get plenty of penetration at shots under 25 yards with 125 grain broadhead on an 1816 arrow, but her accuracy starting off is likely to be better than if she has 175+grains up front.