Hi i have been a Yorkie breeder for over 10 yrs now i have never had a bitch go dry some of the time which is at night

. her pups are 14 days old today she had three pups what i do to get the milk flowing is wash her belly with cold water and rub it helps after about 15 min. has anyone else have this happen ? do you think i should start by bottle feeding them during the day

This is her first litter do you think this will happen again ?
Thanks