LilMissMarshmallow (commonly abbreviated to LMM) is an ACN member who replaced Silver after he died. She is a spammer who's posts are illegible and inappropriate, similar to PorkyMinch and Jedward Cullen. Her account is owned by FuturisticKitty.
After Porky "magically" disappeared, LMM looked all over for him. She secretly had a crush on him, after working as his maid. She shouldn't know how to love, as she wasn't programmed to do so, but she thinks she learnt. When she found him, she started spamming ACN until Porky liked her. Now she is an a relationship with him, although he is also in a relationship with Jedward.
Lil Miss Marshmallow doesn't really have a family, as she is a robot and was built. The only person who she can really class as family is Porky, who is her "lover". She had a child with him, who is called Lil Miss Porkmallow.
LMM doesn't have much of a personality as she was programmed to act like a robot. Although, due to faulty wiring, she became very spammy and inappropriate.