We've done many organized trips. Since I bike with DH, they were not woman-only tours. That said, on every trip we've been on there have always been solo travellers with us -- 50/50 split male/female although some trips have only women; others only men.
As stated earlier, it is the group that you travel with that really makes a difference. We've had aggressive, over organized leaders to laid back, let's all play-it-by-ear leaders. If you take the attitude that every trip is different and that to make the best of whatever Mother Nature or the fates of group organization throw at you, you'll have a great time.
We've done some Europe, but the last couple of years (when salaries dropped) decided to spend more time exploring US/Canada. We've had great trips in Kentucky, Glacier National Park, Burlington Vt to Quebec, etc. Each was different; each was great.
My suggestion....figure out when you want to go. Call and talk to the tour operators that are running trips at that time -- get references and talk to them, too. Figure out what you're looking for in a trip (e.g., riding distance, terrain, food, lodging, side trips, etc) and make sure you ask about those things to the company and the references. We've been on trips that we thought were awesome, but, trust me, some of the people we ride with would not have tolerated the terrain, or the lodging (hey, give me clean sheets and a shower and I'm happy, but other aren't).
That said, our two favarote domestic groups are Timberline (basic accomodation, it is about the riding, food is nourishing, but not 4-star. They do, however, attract low-key, fun people and since every week is some place new, the leaders are not bored with the route -- although they may be exploring it right along with you)
...and Go Sojourn (fancier, lighter mileage, it is about the experience, not the riding, more upscale, good food, nice lodging, planned side trips, etc, yet still not as pricey as some. We went from Vermont to Quebec with them and it was one of the best vacations we've had in many years. Some guests may get....uh...demanding, but the guides are amazingly good about reining them in--heck, watching the guides in action was almost worth the cost of the trip ).
2009 Waterford RS-14 S&S Couplers - Brooks B68-Anatomica - Traveller
2008 Waterford RS-33 - Brooks B68-Anatomica - Go Fast
2012 Waterford Commuter - Brooks B68-Anatomica - 3.5-Season/Commuter
2011 Surly Troll - Brooks B68 Imperial - Snow Beast