If you're into this sort of thing, here is the video I made of myself and hunter guildie Lowjin 2-manning Sindragosa 10 Reg this past Sunday. We're both Marksmanship hunters - forgot to put that in the post title.
As a lvl 85 team of 2 hunters, there's a different set of concerns as compared with the fight as lvl 80. Frost bombs are almost inconsequential, for example (I ignore one in the beginning).
Sindragosa does almost no damage to lvl85 pet tanks in her first phases. Because of that, I elected to use a DPS pet instead of a tanking pet. And that made things interesting in the last phase when she actually puts down real damage on the pet. haha.
BTW it's possible for a hunter who is specced right to take her to the enrage timer. You spec/flask/etc for a bit more self-healing/frost resistance than I did in this video kill. The strat is almost the same, but you eat all of the frost bomb damage. You bandage when your DOT vanishes as she is flying up to start air phase. Doing this wouldn't make for a remotely-engaging video, though. As far as the possibility of killing her solo goes, the frost tombs in the last phase are too frequent to manage in the same way as you can earlier.
Other than that, if you want to read about how the strat functions, it's in the Youtube description section of the video.