Often 2 sizes of female crimp connectors are available.
Maybe like 22ga and 18ga.
So use the larger gauge (18ga) if you are crimping 2 wires in the same contact.
Molex does not officially rate those crimps for 2 wires, but I've done it many times.
Crash course in crimping:
https://pinside.com/pinball/forum/topic/vids-guide-re-populating-playfields#post-4545041