Hi A.,
I am so sorry to hear you are having so much trouble with your little girl hitting. I know it can be a frustrating thing to deal with and yes your right it can also be a double edged sword, with not knowing how to handle it.
Well my little ones have had trouble with hitting and my two year old daughter still at times does hit. But it isn't as bad as you have to deal with.
My suggestion is if she has a favorite wubby, animal, doll or anything of that nature it be a leverage tool. Say if she hits, tell her "I will take your ****(toy) if you hit anyone again" "and tell *soandso* you are sorry for hitting them and you will not hit them again" Try to explain once again that hitting is not nice and you could hurt someone very bad. (I don't know if you have tried asking her why she hits, I know my two year old just says because or because I hit, so she isn't understanding that level but your little girl maybe a little more articulate" If she hits again take her priced possession...and when she cries or gets angry Isolate her, put her on her bed, in a chair away from everyone for two minutes. I know it is hard to talk over a child that is screaming in anger or tears but let her know when she is finished you will talk to her. When you physically remove her from time out then tell her that HITTING is not nice and can hurt badly and will not be tolerated. This may take a few times to let her know you mean business. Then she will not get her ****(toy) back until the end of the day (and only if she does not hit again by that time, and when you catch her in the process of hitting stop her before she does it and remind her you have *** and if she wants it back she is not to hit).
Also when she asks for something special, say in the store or a treat like ice cream or something she gets as a reward, remind her she will not be getting it until she stops hitting other people including mommy. I don't know if this will work but CONSISTANCY IS KEY!!!! I know this all sounds like allot of information for a 19mth old but you have tried almost everything else. I sure hope you get through this. I am also a stay at home mom and find these situations very tough to deal with alone so email me anytime you need to vent or just talk.... Best of Luck with this one.... A. (____@____.com) www.busymomsworkathome.com