cindy,
congrats.
can't help you here cos both of them sleep with confinement for the 1st month and then alone in their cot in their room after that.
if you want to move yenn out then i suggest you start now. way before #2 comes, this is not give her the idea of you don't want her once #2 arrives. it also give her some time to get use to co-sleep with maid.
maybe you can put her to bed yourself instead of your maid. i believe she will sleep much earlier and wake up later then maid right? if you still give her attention, i think it should be ok.
critical period could be the first few months when #2 arrives. try to give her as much attention as possible just like now. cos #2 will most likely be spending time sleeping and not needing as much attention. get her involved with #2's activity does help but don't force her if she don't want. if both cry at the same time, i will give attention to #1 before #2. slowly then try to be equal and also as #2 grows, she will also demand for attention.
during my confinement for #2, hubby don't get to carry her at all. cos yu ze get jealous and refuse papa to carry meimei. he will whine and cry if he sees papa carry meimei. as days goes, slowly he accepted the fact that meimei is going to be permanently there and be with us. now becomes, papa carry mei mei and i carry him cos he wants it this way.
if we out with stroller and yu ze wants to sit instead of letting yu xi sit. i will get him to ask permission from yu xi. he will have to say, 'mei mei, can i sit'. only after he say that, then we will say ok, mei mei say ok and carry yu xi out and put him in.
i believe you have also started to 'educate' her about having a meimei bah. give her some time and she will get the idea of mei mei is going to be with her to share and play with her.