My SIL lectured my husband about not sending enough money to his family

My SIL sent my husband an essay the other night about not sending “enough” money to his parents back home.

We just bought a house, have our second baby due in 2 weeks, my husband is the sole provider of our home. He sends money to his parents every month. Apparently it’s not enough and she gave him a huge lecture about it (mind you, she’s married and lives with her husband and family).

I was beside myself reading the messages - I’m so angry and hurt that she could disregard me and my family and think my husband should just empty his pockets for his family.

Please some advice on what I should do in this instance. Thanks