Poor form? How long should they have waited? I'm not trying to be nasty to the OP at all, but an email was sent (can't tell you why they didn't receive it-maybe they thought it was junk mail, or maybe it went to thier junkmail -- who knows.). As far as they knew, the people weren't interested in rebooking.
Here's a thought: why not go to the box office the day you arrive in NY and explain the situation. (Bring proof of the purchase or cancellation or something) Maybe they can bend the rules for you to sell you standing room or put you first for the cancellation line or SOMETHING. (I know a telecharge rep would NOT be able to do this for you.) Don't be afraid to mention your pregnanacy as a reason to avoid the line and THEN later standing for the show. (And depending on HOW preggers she is makes a big difference on how long she can/should be standing.)
Also, remember that sometimes more seats get released (house seats) as you get closer to the date, so you can also keep checking.
Best of luck!
If we're not having fun, then why are we doing it?
These are DISCUSSION boards, not mutual admiration boards. Discussion only occurs when we are willing to hear what others are thinking, regardless of whether it is alignment to our own thoughts.