Dwyer

[MeddlingMage]

Between Beruka and Peri, who is the better mom for Dwyer?  Ignatius will get the leftover mom.

[Interdimensional Observer]

Peri is Dark Mage for her class offering, while Beruka's is Wyvern Rider. I'd say Beruka wins here due to Dwyer's Magic being too low with Peri as a mom to use magic. Plus Lifetaker, Heartseeker, and Bowbreaker aren't as good as Savage Blow, Strength +2, Rally Defense, Trample and Swordbreaker. Plus Dwyer can wed Ophelia if he wants Dark Mage skills, he can't wed anyone and get Wyvern (unless Corrin/Kana has Wyvern as their second).

On the growths side, Peri gives 10% more Strength, Speed, and Resistance- not bad offensively. Beruka gives 12.5% more Skl, 7.5% more HP and Def, 5% more Luck, and 2.5% more Magic (still useless though).

Strength +2 and Trample can sort of counter Peri's Strength boost, though her Speed lead remains if you care about that. Beruka's Skill lead can be mitigated in turn by Heartseeker, but the Defense gap remains.

On cap modifiers, for Peri, it's +1 Str, Spd, and +2 Res, with -1 Skl and -2 Def. Beruka gives +2 Skl and Def, with -1 Str and Res, -2 Spd. Jakob already gives +2 Str, Skl, and -2 Mag, -1 Lck and Res. Though do remember children get an automatic +1 modifier to all stats.

In terms of caps and growths, Peri is better. But in terms of skills and classes, Beruka is. 

I'd go with Beruka.

[Ertrick36]

My tactical mothering decisions (a term I never in my life thought I'd use) are mostly based off of what classes are given and whether or not the mother's growth rates will have a significant impact on the kids growth rates (whether positive or negative).

Given that Dwyer will receive a class he's total crap in from Peri, while Beruka will give him a class that could potentially help boost his defenses (never a bad thing, imo), and given that most differences in growth inheritance don't seem to exceed 10% (and cap differences don't exceed 2), I'd be inclined to say Beruka's the best mother.