12 mo girl getting way too frisky

Long time lurker, first time poster on this particular board. This is a very nontraditional sitation for this board but I am looking for any help I can get. 

 I care for 8 infants in a daycare setting and recently my little star, we'll call her A, has been extremely attention seeking and trying to hurt her smaller friends. A is 11 months old, will be 12 in a couple weeks. She has always been extremely clingy, wants only me, has high levels of stranger anxiety (especially with men)  but despite all that is a beautiful little girl and just a little pixie / spitfire with a friendly outlook on life.

Recently, however, her little world has been turned upside down due to new enrollment - 3 little new invaders are constantly needing my attention- and she has been acting out. While smiling to make sure I am watching, she will go over and "attack" these smaller kids with her hands, nails, grabbing hair, and maybe even placing her teeth on them (I do not think she is biting them, trust me, I have way too much experience with that and know she is just slobbering them up a little).

This particular day care believes in the "least restrictive environment"- meaning swings, bouncy chairs, and exersaucers are extremely limited and they believe babies should be on the floor as much as possible. This is great and all but I am only one person (yes of course I have a partner, its a 4:1 ratio, but I am head teacher in this classroom and A has been my world and vice versa, therefore I am basically chiefly in charge of her). I have talked to her mother about her big brother (4 yr) being an influence on her, because he is very handsy with her as well, and in my opinion way too rough.

 I know this is not exactly the right place to post this. I am a day- care provider, not a mother. But I consider myself her guardian, her securest attachment, and yes I raise her. I love her very much and just want to help her before she gets in real trouble (of course they wouldn't *do* anything to her, but worse case scenario she could be dis-enrolled  and I would just die if it came to that). Of course, I am also concerned about the littles and their parent's reactions.

 I am looking for the reason WHY and also steps to help her. A friend of mine with a similarly aged daughter says it could be she is about to walk and is therefore just at a developmental stage where she is going to be difficult. Any experience out there? Especially those with multiples, or 2u2, or more? I would LOVE to hear from you.