Question on Dwarf bunnies help?

I have wanted a bunny again for about year. Last night at the swap meet there was a lady selling dwarf bunnies and she had what she said we're the parents with her and they we're small. My question is do they really stay small. I never heard of dwarf bunnies. But when I saw this one I fell in love in seconds so I bought her. If anyone has any information on them that would be great. I read online they only get @ most 5pounds. But is this just what people say to get you to buy them? (like with the mini pig where they say it's only 10pounds fully grown) or do they really stay small? the cage I have is only for bedtime when I go to sleep.it's a small cage not to big or fancy a little bigger than a hamster cage as I bought it with the bunny last night. But when IM awake which is normally 5 am to 12 am daily she is going to have full access to whatever room of the house I am in. The lady I bought her from is a private breeder of different animals I have bought birds from her before. She breeds birds only parakeets and cockatiels, hamsters and bunnies. So I trust her when I buy from her because I have never had any problems from her animals before. Anyways dwarf bunnies do they really stay small and any info you can give me on differences between them and a regular bunny I had one before but not a dwarf. Thanks a bunch.