Being a daughter and a daughter in law as well as a new mother in law brings in so many divergent perspectives simultaneously. One doesn't want to repeat errors even inadvertently. One doesn't want to tread on toes. One wishes to be able to let go, let be. One wants to be as inconspicuous as possible. After all one has had one's own share of life though some parts involved trying to fit in, trying to assimilate, trying to blend in. And all during a time when trying to create one's own pattern was considered transgression of family norms. One should not seek one's own niche in the next generation's nest. One should remember it is their time to create and foster their own. One should not keep yearning for one's past. One should not attempt to recreate one's past in the younger generation's present and tamper with their future. One should remember one has had one's go at it and if one . ...not made use of it optimally, the next generation should not be made to pay for it. Sit back and enjoy watching them going for it. Help if and when asked. Let them create their sacred memories. You don't have to belong to it. Your picture is complete. Hang on the wall unobtrusively. Lend a few hues now and then if they wish so and let them decide how to mix the colours to create a new, fresh, unique masterpiece.
There is no need to treat the MIL as a mother or the DIL as a daughter, be ause don't we know that one can be super critical, harsh and taunting with one's own- such is the liberty within the relationship. Instead behave in the way you would have liked your MIL to treat you, or in the way you wish your daughter is treated by her MIL...