Then listen and validate. She is learning what single parenting is like and will be acting out a lot. You will continue to parent the best way you can, be a steady, stable lighthouse for those boys. Do not defend yourself, simply say something like, "Yeah, this stuff is a steep learning curve, thank you for the suggestions." Then crickets unless she has a real question about the boy's needs.
The only thing you can control is your reaction to her stabs. Sometimes lob a compliment her and knock her off her soapbox. "Packing the boys stuff made me realize how well you multitask at these things." Trust me, she'll be like...wha???
M 10yrs T 13yrs BD #1Oct 2015-PA between WAH and COW BD #2 April 2016-WH resumed PA, she broke it off Jan 2 2017 WH says he wants divorce April '17-Letting go 2018 D busted DD8, DS6, DS3