Is mother's milk tea helpful in stimulating milk supply?

Yes. Mother's milk tea contins an herb called fenugreek. Fenugreek is helpful but you've got to drink lots of tea. Better yet, take fenugreek capsuls 2 caps 4 times per day till your milk supply improves. Frequent breast stimulation by putting your baby to breast or pumping at the same time helps too.
Yes. Teas containing milk thistle or fenugreek can help, make sure you're drinking plenty of other liquids as well.