Going by all the gig clips she's posting on FB she's doing what Overkill do and playing smaller venues and getting in crowds that really get into the show. I don't reckon I've seen a clip from a venue with more than about 3000 people in it (although some are hard to tell), yet she's been touring the US with Metal Church and on her own for more than three months now. Even with days off that's an impressive gig list.
Our problem here is the distance, not just to get here but between gigs. Feasibly someone like Doro could play 5 shows in the same venues Overkill did (about 2000 cap), but it's pretty much two days out of the schedule to get here, flight time and recovery etc, unless you come from Japan or somewhere in Asia. Then you can do Melbourne Sydney, Brisbane in three nights but it would be hell on the band and crew. If they could organise the gigs in the right order Adelaide could be a fourth night, but gigs rarely happen in that order. Then to get to Perth it's at least five hours by plane, 20 by road. So even without rest it's easily a seven day trip to tour here. That's does make it hard, throw in some rest and recovery and you could easily spend two weeks here that could have seen 10 gigs in the US or Europe.