This is where it gets challenging. I wouldn't want to discourage you from writing because someone on here (whether that be SHAUN or some other poster) is bound to write now due to this question, irregardless of what I say.
The thing is, the creative team pretty much in general don't respond to mail -- or any of them that I've ever written to. Once a production opens there practically never there (especially considering that she's an A++++ Celeb), for the sole fact that it's a done-product. Once previews are done and "Opening Night" happens (April 30), it doesn't matter if they change the show around because the critics don't come back. Therefore, they don't make the changes...! So since she is the composer (& the lyrcist), she sort of needs to be there morethan once each week, incase a lyric is out of place, or they need underscore there...etc.! And as I said before, she was there the entire Los Angeles run..and once she actually entertained the audience when they were having technical difficulties

! And the composer/lyrcist/book-writer/designers/casting people/cast/crew, will all definately be there on opening night - it's their party to celebrate the [great] product they put together and hopefully the good reviews.
So will SHE respond to the fanmail is the real question. Since everyone keeps insisting she's a hard one to get and doesn't frequently sign, I don't see why she WOULD respond via the Marquis Theatre. And who knows, she seems "kooky" (in a GOOD way) enough to even sign the cast-signed playbills that are the Opening-Night ones (Jill Santoriello, composer/lyrcist/book-writer of ATOTC signed some of them!). So you may want to attempt to get one of those too.
So in short, I'd try to get her autograph there (if you don't send before opening don't even try -- that'll just pile up until June (Tony Awards) or get tossed probably), but I probably wouldn't send the '9 to 5' cover, unless you're not too unattached to it. It would be pretty awesome to have her sign it and I'm sure she'd be glad to sign that -- who knows maybe she'd have Megan Hilty (whose playing Dolly's role in the musical), Stephanie J. Block & ALlison Frasier sign it as well, if you wouldn't mind.
Hope this shed some more insight...! I think you should use the policy that's always used with VV -- if you're attached to it, don't send it; if you're willing to lose it this short period is the ONLY time you'd be able to get it in this run. (Unless she becomes totally bizarre, gives herself a AEA Card and performs in it? HAHAHA Wouldn't that be itneresting!).
You could also attempt to stage door at the Marquis. It's a goofy theatre -- on the 4th Floor of the Marriot Marquis Times Square. The stagedoor is right below where the big Marquis is, facing Times Square I think,...just show up about 2hrs 15minutes ISH (maybe even later) and she'll probably come out (although with EVERY star there's never a GUARANTEE). Opening parties are not able to be done with what happens with teh A list people, so that'd be a rare opportunity to potentially meet her!
Anything else, post here or PM me! I'll try my best to answer..!
