well. I haven't experienced this but my son wants to blow his nose constantly. After years of telling him to stop it or get a tissue.... I finally started just handing him a tissue without saying a word. And lo and behold, the blowing has decreased and getting a tissue on his own has increased. Yahoo.
So if your daughter's spit issue is similar. You could just silently hand her a drink or a tissue without saying a word. Over time, she'll realize thats what she should do. I think this is one of those things where you should give very little attention but give her a soltution.
It has been three years since I've been on-so I just want to say thank you for your input,my daughter Iauna is still spitting,it has decreased but hasn't stopped,So I'll definitely try the method you told me about!👍🏼