Sounds like it will be a major drain on you to go. Can you just send a letter to MIL offering your condolences and explaining that you didn't feel it was appropriate to go, given then circumstances?
Me-47,XW-43 S13,S16 M:18 BD:4-23-17 W filed:7-17-17 (5 months of in-house separation hell) W moved out:1-6-18 D granted:2-15-18 Decree signed:3-29-18