Critical/jealous friend?

hi, i have this friend who is really annoying me. i think it may be jealousy. she is a snob and i look past this and just ignore it but she is a total ***** with my daughter. she seems to hate the fact that my daughter is loud and confident, but thats her personality and i embrace rather than knock it. its not as if my friend czn say anythin becuz she is a loud person. yet when speaking to my daughter who is six btw, she constantly tells her to be quiet, or say "do we have to shout" and tells her to use her manners and basically nitpicks every little thing. thing is my daughter uses her manners, she is friendly and bubblyand everyone, inc family, friends, teachers etc love her and think she's great apart from my friend who does nothing but nitpick. i work with kids and have done for 5 years and i understand how things she says can impact on my daughters confidnce if she carries on. her partner has his own two kids frm previous relationships and she is same with them but thats not my business my daughter is mine and she shud keep her nose out cuz it gets to me that she tells her off when im there??? like if she doin summat that i dont like I will tell her ya kno....and my friend will also kinda like "snitch" on my daughter to me about stupid things that my friend expects me to tell her off for and im just like "oh well she a kid int she thats what kids do" i have told her about this before but we fell out for a while and have recently made up but she still the same towards my daughter. thing is i kno if i say owt she will take it seriously to heart and we will end up not bein friends which i dnt want i just want her to understand kids shud be embraced not seen and not heard and nit picked at :( i think my friend does have quite low self confidence even tho she acts confident, and i think the fact i work with kids she feels she has to prove herself that she is just as good as me with kids if not better?? any advice on how to deal with this friend before i snap??