Overly critical mother-in-law

My husband and I got married young, both of us at the age of 21, now we’re 23 and coming up on our second anniversary. His mother was always generally a pretty sweet person, but when it comes to parenting choices she is so critical.

A couple months after we first got married, the inevitable “when are you going to have kids” topic came up during a family reunion, and my MIL responded before we could answer with “you guys are WAY too young to be parents.” Granted, this may have been true, but that was unnecessary for HER to interject. Fast forward to now, one dog and one cat and no children later, she comes over to our house for a surprise visit. When she sees how much we love our pets she says, “I *personally* find it so bizarre how millennials these days are getting married, having no kids, and then making their pets their babies... but that’s none of MY business...”

She’s also made comments about my sister in law (who has four little ones now) saying how she has SO many kids and her decision to pump instead of breastfeed. Why does an otherwise “gentle” person feel the need to say these things? Her comments to me and my husband are also contradictory, like what do you want from us?