Oh In-Laws...

Courtney
So, a little background: I'm due with my first at the end of this month, my sister-in-law is due with her second a week after me. She's convinced she'll have hers early, I'm pretty sure mine will be late. She wants her mom (my MIL) in the delivery room with her and her husband. She wants her dad (my FIL) to watch her 3 almost 4-year-old while she's in labor. My FIL is a teacher, so she's worried he'll be stuck at school when she goes into labor.
Last night, my MIL came to me and my husband and asked if I could watch my nephew if my FIL can't get there. I swear, both my husband's and my jaws dropped. We didn't say anything for a while. Finally my husband said "You know she's pregnant, too, right?" And I said "And I'm due before her..." My MIL said "Yeah yeah, I know, but she really needs the help." So I kinda stammered something out about IF she has her baby first and IF my FIL can't be there and IF I'm free and IF someone can drive me (I work from home so we have one car) then MAYBE I can POSSIBLY help. As soon as we got in the car to leave my husband kinda went off on how ridiculous of a request it was and how he's not comfortable with me watching this crazy high energy kid at 38+ weeks pregnant (Seriously, this kid kicked me in the head last night and grabbed my husband around the neck with no warning and the family just brushes it off and lets him do what he wants).
The craziest part of all this to me is that my SIL didn't even ask my MIL to ask me. My MIL took it upon herself to find childcare for her. My SIL still, to my knowledge, has no clue this happened. Finally, after getting home I composed myself a little and let my MIL know that we weren't comfortable with it and she needed to find a more reliable back up plan.
Is it just me (and my husband) or is that kind of a crazy request to ask a more pregnant woman to watch your kid when you go into labor?