There were photographic films ( undeveloped obviously ) found burnt in the stove at Ipatiev by the investigators,this implys that other photos were taken at Tobolsk or on the way to Yekaterinburg which we will never see .Their cameras were confiscated on arrival at Ipatiev so none were taken there. There are quite a lot taken at Tobolsk which have been around for many years ,most posted on this forum or elsewhere on the web. There may be others that we have not seen which may be in private collections,who knows ?. Nothing seems to have surfaced of recent years........
As for Marie doing the developing - that was actually Anastasia , in one book ( cant remember which at the moment ) it is said that Nicholas actually paid for a representative of the Kodak company to teach her how to do it as she had such an interest in photography - of course Marie may have learnt from Anastasia.