could be a bladder infection. let the vet check her out! dont' let you puppy drink all the time. if a dog or person drinks too much water they can give them selves water poisoning and could die !
i had a weimaraner that was addicted to water. came from a puppy farm which i found out later. i adopted him. he had to be put to sleep at one anmd a half years old!
but bladder infection could cause the pup to drink more or pee more. also diabetes could cause this berhavior. diabetes also causes a pup to lose weight.
my advise let the vet check her out. it might be nothing but atleast you'll be sure shes healthy!