So, let's see...
Sigurd x Deirdre
Sigurd is totally wasted on that blank slate that is Deirdre and her stats are terrible. Nihil can be good for bosskilling some of the last chapters, but almost any other mother give much better skills. Bleh.
ok I'll do it seriously now
Noish x Ayra
Quite good, gives to the siblings the skills Critical and Charge, making them way more lethal (which is surprising) and even better at bosskilling. Their stats are high but they don't get the absurd DEF Lex gives them, though Lex's skills aren't good on them.
If you want to slow down your play pace and make them reach bosses, they will be even more devastating, expecially against some of the last game bosses.
Lex x Raquesis
Fuck, no Pursuit. Both Delmud and Nanna have good equilibrated stats in general and need only Pursuit to start being great, and this pairing doesn't give it. Also Delmud has no problems at killing or keeping up (neither Nanna with her healing) so Elite is wasted. Lex can't pass good swords to his son, also. They just get a very high defense. If you don't give to Delmud the Pursuit ring or the Brave Sword his killing will always be bad, but having to use the Pursuit ring on someone that usually already has the skill is a shame. The Brave Sword is best used or on Seliph, or on him, so giving it to him is a great idea, but he will struggle against some hard enemies that normally he would have hit four times.
Nanna's fighting is lost.
Azel x Tailto
Besides Levin, Azel is the best pair for her, so no problems here. Artur will have all the skills and stats he needs and be very equilibrate and good at existing.
His sister is generally bad because she's bad, but unlike her brother Azel is even better than Levin thanks to Pursuit, so she's at her peak. A very low peak, mind it.
Lewyn x Ferry
Her best pairing, his second best pairing. You did good, though Fee has better fathers, like Noish, for helping her physical side. But with a bit of work and waiting she will become good. Just, give her a magical sword, she will use it really good.
Jamke x Aedan
Lester is bad anyway, because he uses bows, and without the pursuit Midir gives him he will need the Brave Bow, which he's the only user anyway. With Midir as a father he can use natural Pursuit and Brave at the same time, though, but nothing of real importance was lost.
Jamke can be a great father for the twins of Ayra, if you want to use Noish for make Fee at her best and Levin for Artur.
Claude x Sylvia
Well, ok. Claude can be the father of Levin for making a fantastic staff user, but besides that, not much. Sylvia's children don't care about their father anyway.
Holyn x Briggid
Holyn gives a lot of SKL and HP and he's the best with Briggid: Faval gets what he needs most, accuracy, and Patty can belive she's a combat unit with a better sword rank, bulk and Luna. She's not.