Ophelia Dusk

Really, it depends on what you want each child to have. Lethality is really good on Nina, so a Nina and Asugi pairing is recommended. Rend heaven is brilliant on Ophelia so Ophelia and Shiro are reccomended. Also, download this app! It has a lot of friendly people and is really fun. It's a place for all the FE fans. They could help awnser your question! Here is the link- http://aminoapps.com/c/fire-emblem-amino