2nd Perfect Guidebook, I think.

icon love.

XD They never actually mentioned Riza's name in the manga; though it's as ceasefire said, it was made official in one of the Guidebooks.

It's chapter 25, "Resolution between master and apprentice". Grumman asks if Roy will marry his granddaughter.

It's never mentioned in the anime, so I wouldn't consider it canon in anime!verse.

Well that's odd considering her father doesn't seem to like military dogs, hehe.

Yet Riza joined the military after her father died, so either Riza didn't agree with her dad's views or there's some pieces to the story puzzle left to be unravelled.

Which is probably what is going on. Seeing General Grumman is most likely her Materinal Grandfather and we have not met Riza's mother those issues may play into this as well (BTW, do we know if Riza's mother is dead? While it's likely her mom isn't alive, I don't think it could be ruled out the possiblity that Riza's parents were divorced, either. If the latter was the case then her mom could still be alive (but my gut feeling at this point is Riza's mom isn't alive - I'm just tossing out some possibilities here)).

haha it says he HAS a granddaughter, not that she's riza nessecarily ^^

(unless you were noticing the few people who refered to that very page i provided seemed to think i didn't know about it...) or something
haha

yay!

As others have already said it was confirmed in the second perfect guidebook. It is not anime canon but it is manga canon.