Thank goodness for the growth in singles travelling as now there is a good economic reason for companies to look at developing great offers for those looking for holidays for one.
Around 60% of people who go on Explore trips are traveling on their own and they break down solo vacations into age groups on their website which is really helpful.
The heart of the community is their Facebook group, which has some great information and is the perfect way to meet other females interested in traveling solo.
Australian based Travelling Divas also promises boutique hotels and customized trips. I have also been very keen to try Cox and Kings solo holidays.
I would highly recommend that you think beyond the country you live in when it comes to solo travel groups.
An interesting-sounding organization is Archaeo Adventures. They are about boutique hotels, working with locals, and off-the-beaten-track experiences.