Depending on how long the siege lasts Dany might be able to bring the dothraki in for reinforcements. At least I hope she does.
I do too, but I don't think it will be easy to convince them to follow her, since she is Westerosi and a female by birth. However, she does have dragons
That is pretty much her "big stick" and the Dothraki are foolish to the point of recklessness if they are not a least a litle fearful of this. This would be a great turn of events, and now that she is riding a dragon, her travel time would decrease. I don't imagine the Dothraki she has came upon will give her much trouble once they piss Drogon off, as I don't doubt they will. Maybe Jhaqo won't survive, and if he doesn't that will be even easier for Dany to take conrol of the Dothraki.
However, I hope she returns to Meereen before the Iron Islands fleet arrives.