I expect the women themselves would just call it a "family", so the nickname would come from others as a way to deride or differentiate from whatever is the norm or average. Nicknames often originate in an insult, but the actual slur would depend on who does the branding.
If couples with a male alpha are the norm, the insult might reference the female alpha being a "false" alpha.
If female couples who are equal partners are the norm, the insult might reference heterosexual pretensions.
"Doll House" says to me that the insult originated in a male-dominated environment, and that a female-only couple is a pretend or immature relationship. It doesn't differentiate between alpha/beta roles, it just references the lack of men.
I don't see other women creating this term as little girls usually don't play with only female dolls, on the contrary dolls getting married is very common in our universe (contrary to TV commercials I don't see little girls pretend their Barbie™ is going to the mall with her girlfriends to shop in consumerist paradise, rather role-play mimics domestic relationships, parenthood, dating and marriage), so women might not see dolls as a purely girl-only experience even if men do. (Men of my generation actually collect more dolls, but they call them action figures.)
Of course over time the insult/nickname might be taken up by the group itself as language evolves. It's somewhat counter-intuitive to remember that "gay" was an insult meaning frivolous and unserious in a time when people were expected to conform to "serious" adulthood – it makes little sense as an insult in today's society where childhood is extended well into middle age. I don't know how appealing "doll house" would be for the female alpha, but she might use it if it was in the common language. You could even "lampshade" it by having one of the alpha women say she doesn't like the term. Discussing the ulterior meaning of words is a very feminist thing that happens in our universe, so if you are worried about offending people you can have a character say what is wrong with it (it's called "hanging a lampshade on it").
There's not enough info about your Omegaverse for me to say whether your nickname works or not, but hopefully this helps to put perspective on it?