who should take care of baby

If you are comfortable with you sharing your maid with your SIL, and also if you bond well with your MIL then it is not a bad idea. But hope it won't cause a complex situation. MIL, SIL, two infants, you... Also, if you get your aunt or a relative at home to assist you then also you have to see that your MIL and SIL treats your aunt nicely. Since, she will have to stay with you for a longer period, she should feel comfortable with you. Also if someone will not treat your aunt or relative nicely, you will feel bad and will have undue stress. The first option though seem little complex, like one maid being shared by two women and also to help your SIL, but I think this still seem manageable. If maid is get scolded by your MIL or SIL, it won't hurt you as much if the same is met out to your relative.

Like what others have already shared, I think #2 is not legal either. Other than that, I'd also prefer to have an aunt that stays nearby if I were in your shoes! Since your MIL has already stated her preference, then I think it'll be better for you to respect her decisions and make separate arrangements for your child - I'm not saying to totally ignore your MIL or not let your child visit, but the main caretaking duties should be under you and your aunt so that both children can get the attention and focus they need from their caretakers. In addition to that, having an aunt that stays nearby would be better for any emergencies - and it's easier for her to help you out too :)

I will prefer relative who stay nearby and able to give one-to-one attention to my baby. Firstly, it will be easier for you to fetch your baby. Also, If your mother in law stays with your sister in law, you may have to worry that they will pay more attention to your SIL's child. Also I agree with Hui Qun that it will be tricky when it comes to sharing a maid. The maid will stay in your SIL's house, she will have the full control of the maid. If you are paying half of the maid's salary, it will be unfair if your SIL demands the maid to do more work such as cleaning the house than caring your baby.

How comfortable are you with your aunt who lives nearby? If I were in your shoes and am close to my aunt, I would opt for the first option. I feel that it will be tiring for your MIL to take care of two babies even with the help of a maid. And sharing a maid with SIL may be tricky (over the work distribution and stuff). It is also better if your aunt can help attend to the baby fully as infants would require a lot of attention and comforting. Having just one or two consistent primary caregivers will be less disruptive and help them feel more secure.

i feel going with the second option is good if you are very sure that it will not cause any issues in the family. simple things such as who is tended to more and when by the maid and when by the MIL could also lead to problems and jealousy. if you have another relative nearby who is willing to look after the baby, go for that option because baby will get undivided attention and it will also not give rise to any conflict within the family.

To me ,if i have a mum i will ask my mum to take care of my baby instead of MIL. It will be hard for MIL to cope 2 babies at one go... And usually there will cause a lot of problem if you choose to put both at home. Otherwise you can look after your own child or put your baby in infant care. Or relative aunt who stays nearby if you guys are close enough.

i would choose the first option as it will give the liberty of doing things without worrying if you are taking away from your SIL's time. of course your MIL and you may have shared a great rapport and she helped out earlier, but now that she has to look after the other baby too, i think the first option makes more sense.

I will get my aunt to look after. With maid, many problems will arise. Whose clothes is the maid going to wash. maid will be hired under your name, but she can't work at other household. There will be lots of problem and conflicts too.

If you are okay with your aunt than i would prefer the first choice. I'm afraid of conflict that might arise when your mum and maid look after two newborn together. Alternatively have you consider to get a confinement nanny instead?

If I am in your situation, I will choose Option No.2. This is because I prefer one to one attention when a baby is still young. Imagine 2 babies are crying together and your MIL will be at lost what to do.