I know what you mean about shoes. My son's feet are also very narrow and it's just so difficult to find anything in normal shops that fits. Russell & Bromley are a bit better at doing some shoes in C fittings than Clarks are. My ds is pretty much OK without piedros, now, so long as he has well made shoes - his ankles pronate and feet are very flat, but it doesn't seem to cause him pain, and he doesn't seem to tire any more quickly without them than with, now that he doesn't lock and then flick his knees to walk any more. Hopefully he won't need to go back into them when he's older, although his rolling ankles do get commented on when we go to get him shoes, as if we hadn't noticed!
Ds does think it's funny when I ask him not to bend his elbows and fingers back the wrong way. I haven't seen what he can do with his toes, yet, although my husband says mine make him squeamish (I'm hypermobile myself, but not in any way comparable to my ds).
Clothes are definitely an irritation. Ds's trousers would fall down to his ankles if we didn't tighten the adjustable waistbands as much as possible.
I don't think my ds has any problems with his eyes - he did have them checked at the hospital but there was nothing unusual to report and his vision was normal (unlike mine - I'm dreadfully short sighted). We haven't had any checks done on his heart. He doesn't have a high arched palate or other unusual features, except for the marfanoid habitus, or none that have been commented on by the paediatrician.
It will be interesting to see what the specialist thinks of my ds - if he lets her examine him (part of the problem with the paediatrician is he's never let her near him!). I used to be terrified of what might be wrong with him, but as time's gone on, it's become obvious that he is getting gradually stronger and more stable, so the likelihood is that it is a benign condition (although I find that a slightly irritating term, as it implies it's harmless, rather than simply that it's something that won't shorten his life).
As for help, we did get physio, which was invaluable, and he's still on their books but no longer seen - unless he starts to experience pain. He's been reviewed by an OT who will from now on attend his reviews with the paediatrician (as does the physio, if they are all free at the same time!) and has given us some exercises we can do at home to help strengthen his shoulders, arms and hands as much as possible. If my ds had greater problems than he does, I would have been rather upset by the amount of time OT and PT can spare for each child on their books, but my ds was always a willing participant in the exercises we were given, so we were able to work on everything at home and make progress.
Gosh, that's a rather long message, isn't it! It's nice to have someone to let it all out to! Your dd is obviously more affected day to day than my son and (hopefully) my son doesn't have issues with his eyes or internal organs, but a lot of the difficulties they experience sound similar. I'm hoping the specialist can confirm my ds doesn't have anything too serious wrong with him without doing too many tests on him, first!