MIL makes rude comments about my baby son - what do I do?

Apologies for formatting - I’m on my mobile.I’ll try to make this short. I have a 5 month old. He suffers from reflux and so can be tricky to feed. He is generally really smiley and has a nice disposition but tends to really cry when he’s tired or when the reflux is playing him up.I am told by my MIL that my husband was a model baby - slept through the night from birth, never had any feeding problems etc. My nephews (BIL’s kids) were also ‘good’ babies according to her. My recollection is a little different - nephew #2 was a real little grump.We don’t see my in laws often even though they live close by but it seems whenever we do go my MIL makes a fuss when my son cries and compares him to other babies. She makes comments like ‘what on earth is wrong with him?’ and ‘Jesus Christ - I’ve never heard a baby scream like that’ and ‘I can’t believe he isn’t sleeping through the night’. At first I brushed it off but it’s really starting to get me down. It feels like she thinks my son is abnormal (my mum assures me he isn’t) or that I’m doing a bad job.My husband is really supportive and does pick her up but he’s not always in the room when she says things.Am I best just ignoring it or should I say something? I’m not sure I can say something without losing my temper but I worry she is pushing me to that point anyway.TL;DR My MIL makes rude comments about my baby son’s crying and it’s really getting me down - do I say something and if so how do I approach this without falling out with her? via /r/Parenting http://bit.ly/2RcZJMY