Can't "ask to be roommate"

[Prinzessin Kirara]

I'm trying to get two of my sims friends to become her roommates but the "ask to be roomate" social does not show up (they both are good friends with my sim).

I have all Eps and Sps.

[Zyffyr]

1 - How many people are already living in your household? Roommates count towards the 8 Sims limit.
2 - How many beds do you have? IIRC, unlike the "Ask to Move In" interaction you can't get someone to be a 'roommate' unless you have a bed available for them.