Hi K.,
I'm a US born, first generation (caught between american and traditional asian culture)Filipino American SAHM to a beautiful 3yo little girl, married to a Polish American(caucasian) husband and also live in Land O Lakes.
Regarding your MIL, it's not a matter of Asians being overly sensitive or unable to take criticism, like another responder stated. It's a matter of feeling a part of the family, feeling respected, feeling like a contributor and being productive. By all means, take advantage of your MIL's willingess but like other responders said, with your husband's participation/buy-in/support, set the ground rules up front. Your MIL will appreciate it and will respect you more for it in the long run.
Sit down and have a conversation with your MIL. Let her know how much you respect and value her, how much you appreciate her willingness to help and how grateful you are that you have the opportunity to have her be there with you. Then let her know that you're also very grateful that you and her son have the opportunity for you to stay at home with your son and that you want take every advantage of it while you can. That it's important to you to build a strong bond and foundation with your son. Employ your husband to help you think of some things that you can share with her that she can do to best help you, her son and grandson...include some things (that you know she can handle) she can do with her grandson so she has the opportunity to bond with him as well...after all, I'm certain there will be times when you'll want to take a break just to...take a shower, go to the bathroom, have a meal in peace... ;-) Later, as you and she become more confident in her comfort handling your son for greater lengths of time, you may want to take advantage of the opportunity and leave him for longer...maybe so you and your husband can have a "date night". If she feels like you're including her and making her feel like she's part of the family and not just a burden or house guest, you'll win her over and gain a valuable resource.
Grandparents(if you're lucky to have them), are generally very proud and doting, regardless of race/culture. At times, they step beyond the rules we set for our family, which can be frustrating. But isn't that what grandparents do? If they aren't being undermining, harmful and it only happens on ocassion, why not let a grandparent be a grandparent? After all, your child will look to you for to set the rules and for guidance. Grandparents have already done their parenting stint. Now they're just looking to enjoy themselves and have fun with their grandchild. Besides, your MIL raised your husband. She must've done something right if you married him.
It is sometimes challenging...speaking from experience with a very involved, demanding Asian mother but, it does get better if you lay the groundwork up front. Best of luck to you and your family! Let us know how it works out.
Liza