This is why I'm a big believer in EXPonential Growth DLC map. Veeeeery handy, especially in the early going ons for weaker characters like Donnel or Olivia, or when you want Future character to catch up without the hassle of dying (although you do need to be careful with the Lv. 30 Entombed, as they know Counter).
Also, it's pretty obvious that Awakening pushes Sumia for Chrom's wife-to-be (there's even that random cut scene when she rescues Chrom at Regna Ferox). Cordelia's fate when it comes to Chrom is pretty sad though. 
However, I have to say that the narrative really comes together in a special way when you have the avatar become Chrom's wife. The dynamic of their friendship and connection is (imo) pushed even further when they're connected by the bond of marriage. Heck, even the connection with Lucina is pushed further because she's now your daughter (It was a pretty powerful moment when Lucina came to the decision to kill you to save Chrom, despite you being her mother as well).
The concept of marriage and having a family isn't really something gaming touches on often, but for Fire Emblem, it was a great move both for gameplay elements and story elements. Kudos.
EDIT: And another reward for having a female avatar. Tharja is totally willing to go lesbian for you. Kinda hawt. 
"Ah, how sweet. She's sleeping."
"Sleeping... and helpless."
"Hee hee hee hee."
*Avatar and Thaja's support grew to A*
