Janet's Purse (Research)
A sort of boxy envelope purse with a silver chain strap. The lining is black and there is an oval shaped emblem on the front of the purse. The white patent leather is top-stitched, and the flap - which comes all the way to the bottom of the purse - most likely closes with a magnetic clasp under that emblem.
The best times to see the purse on screen are during Dammit Janet and the beginning of the Time Warp.
If you're feeling crafty there are some purse patterns that will probably be more accurate than what you will likely find on eBay. You will need a special teflon foot to sew patent leather on your sewing machine.