why do toy poodles lick so much

I use two or three pats as a signal for that's your lot. I don't like being licked, so mine have more or less learned not to do it, but Poppy tries very ard to lick my face first thing in the morning, and Sophy loves to lick feet - she will even pull socks off to get at them. A rug wrapped round them, and she soon forgets that they are there. I don't think you will hurt her feelings - just redirect her onto something she can lick or chew as much as she likes.

A Kong, or a tug rope dipped in chicken stock and frozen, or a teddy bear if she likes soft toys. It will take a while if she is used to being allowed to do it, and you will all have to be consistent about only petting her when she is not licking, and blocking her and giving her something else to mouth when she tries. At least it is just licking - Pippin-cat is a kneader, with needle sharp claws that penetrate layers of jumpers and t-shirts and skin like surgical steel.
Dogs that have been abused, and many that haven't, will lick to calm you and/or show affection.

Tommy sometimes gets upset with the girls trying to play with him and starts growling(they do kind of attack him). Lady, still playing the mommy role, will run up to Tommy and start licking him to calm him down from growling at her girls, and it works. I think an abused dog is probably afraid of you getting angry, and trying to keep you calm.

I personally hate being licked in the face. When my dogs lick my face I tap them on the head. I don't hit them, just a little tap/shove as soon as they do it, and a firm NO KISSES, followed by more petting to let them know the affection is fine without the licking. Now none of them lick anyone in their face, sometimes on the hand or arm, but not the face.

Dogs don't need to feel pain, but they do need to know what you don't like them doing, and they respond to body language naturally, response to words is unnatural and needs training. I know it is difficult to correct an abused dog, but it is also necessary. Considering that you don't want her afraid of you, maybe some redirect would be a better approach. When she is licking you, gently and firmly say No Kisses and take her muzzle and turn it away from your body.

Then pet her head and such. Keep redirecting her every time she goes to lick, and she should catch on. Eventually, when you say no kisses she should just stop licking. When/if she does, reward her with petting or treats. letting her continue to lick you is definitely not going to solve the problem. Dogs need to know what you want from them, and once you make it clear to them, they generally want to please you.