what should I do? babies involved

Without getting to detailed....my sister in law was arrested on drug charges, her husband is in jail, CPS took her newborn triplets...the husbands mom after two weeks finally was able to get them but is having a hard time handling it and is thinking of giving up and my SIL is out and isn't supposed to be near the babies and we fear that she's been going to her MIL's house to see them, if she has and gets caught then that's obviously really bad....so my MIL talked to my husband and I because my SIL's MIL can't handle the babies.... then either my MIL or my husband and I have to take them....if we don't they go into the system and could potentially be adopted out to a stranger. My MIL wants to take them but doesn't because she feels like her boyfriend wouldn't stay....they're insanely in love but they're getting older and she thinks the nights would be to hard, she's done her time as a parent and wants time to live her life ect ect and my husband really doesn't want us to take them because he wants to focus on our newborn and her life....we obviously are worried our own daughter won't get the attention she deserves if we are busy with 3 newborns ontop of her and my husband is gone a couple nights and days a week for work so I'd be alone for a lot of it.....I'm so torn....I really don't know if our relationship can handle three new babies and everything else that's going on ontop of it all....none of us want anything bad to happen to them just none of us are really in great positions to take them either....we'd be raising 3 newborns and a 3 month old....opinions?