I suppose you could make her a sounding board / sympathetic ear if you decide to write in relationship troubles between one of your existing couples. Really, though, there's no real need to try and shoe-horn her in as it is. I mean, yes, the focus has gone from "Ask Twixie" to "Ask Twixie, and friends, and their extended families" but it is still a Twixie centric blog.
Usually, if the Ask Button is not shown is: A) The artist disabled it to stop readers to send more questions because he/she already have too many; or B) Author forgot to re-enable it after option A happened. Usually, there's only a 1% chances it is option B.
Then you just need to wait until the author manages to get rid/answer some of the questions and decides to enable ask box once again...It may be annoying, but it's the only way on Tumblr you have to prevent to get a bajillion questions and being unable to answer all of them.
Someone do that too...Tumblr gives you the possibility to erase some or all of the questions you got...those who've done that before are mainly people who went on hiatus for 3-4 weeks and when came back found something like 300+ questions in their box (too many to read and answer them all). Also, I don't get the Gildashy question
Actually, I'm more of a fan of PinkieShy, cause I've read more fictions and seen more pictures of that couple and really few with GildaShy Anyway, I think it's ok...I mean, that's the way a lot of people see a possible redemption of Gilda, and I like stories where the antagonists of the show redeem themselves (from Nightmare Moon to Queen Chrysalis). Hell, I'm even writing a redemption story with Trixie myself