My girlfriend refused to sleep train/allow me to sleep train our 20 mo when she was a baby, and said she'd grow out of it. she hasn't. she is still waking 2-3 times/night for milk. how do we sleep train her now?

Sleep train now: Sleep training can be started at any time. Follow a scheduled routine that does not vary daily. Your 20 month old should be eating 3 meals and 2 snacks per day of solid foods, followed by 4-6 oz milk after every meal. At night, a routine of bath, reading/singing or cuddling then put it to sleep in a crib. If she cries, put a hand on her chest and make soothing noises but do not pick her up.