theres lots of info online on how to post/tape and set pups ears (in every breed)
my suggestion would be to use a method simliar to the cresties.
ear taping
i used this with jasper (whos ears are huge!) and now, even as hes heavily feathering out they are up and strong.
remember too, that ears will be harder to get to stay up during teething, but if you dont start traiing them by 6 months its even harder to get them up. so my suggestion would be to tape them now, and keep doing it untill they are standing alone, then keep a close eye on them till shes done teethign (about 8 months for toy breeds) and tape them again if they show any signs of flopping.
rubbing alcohol removes the tape easily, but id suggest shaving the ear first to avoid pulling hairs.
one suggestion, i didnt try as jaspers ears responded quite quickly to being taped, is to give her tums, aparently it helps, and when done WITH taping, alot of folks have great results getting them up and staying up quicker.
personally i like yorkies with tipped ears lol and shes adorable...you can just see the mischeif oozing