Attaching Sheet to Jib
You may also want to ask yourself if the sheets are thicker than they need to be for the sail (it is fairly common for genoa and main sheets to be really larger than they need to be; people just look at 3/8 or 5/16 line with a historical notion of how substantial such lines should look and feel based on rope technology of past centuries and consider it too "thin"; they also believe that thicker sheets are easier on the hands, I suppose). The Mumm 30, for example (30 Ft. LOA) class rules specify 5/16 diameter yacht braid for jib sheets, which has a breaking strength of 1350 lbs., probably two or three times the maximum strength such lines actually need. So seeing 7/16 or 1/2 inch jib sheets on a 22-25 footer does seem a bit of overkill. But if that''s what you like, it doesn''t really cause any problems (not a lot of pulley blocks to run around like the main sheet, and it doesn''t add weight aloft like a fat halyard will).
You can also consider just getting a new line long enough to form the sheets for both sides, attaching it at the middle to the clew. That would avoid the need to have a couple of bowlines at the clew for two separate lines.