The Mum said "this seemed like a long time to me but hey, if my Paediatrician said it, it must be ok.... On the first night she cried for about 2 hours in total and in the end she went to sleep but was still kind of sobbing in her sleep coz she'd got herself so worked up... It was so hard to listen to her cry, I felt sick and my husband had to stop me from going in to her but I just kept telling myself that it's just one week of pain for a lifetime of gain....".
I think this is an opening to discuss the topic, and suggest that there are other ways, and judging by the reaction, would depend whether to give more info.

When this orginally came up, and I said that I think you shouldn't say anything, that was based on the scenario of the mother not seeming bothered that the baby crying, and feeling that it was right for them.

But this shows that the mother is wondering whether it is right to be feeling this way.

BBL, baby crying, so gotta get him fed, and DD off to daycare.