robert blu
quiet photographer
You are an excellent brother and your sister is luckly. I am not so experienced about gear, can only say Bessa are good enough to be used and both 28 or 35 could be good. It depends if you sister is ready to go near the subject (in this case 28 is the choice) or if she prefers to be less intrusive (35 in this case).
regards
robert
regards
robert