Just reading the descriptions and clicking the links (where available) is enough to tell you that there isn't a single functional escort agency in your list. They're all independents, no longer operating, or both.
I don't think anyone on here will be able to recommend a lesbian agency, but if you want to keep looking read
this first. It's for men wanting to escort women, but the same issues apply to you.
A while ago a lesbian escort who advertised on adultwork.co.uk/gayswap.co.uk contacting me because men tried to book her even though she advertised as gay, and she decided she'd be willing to do ffm threesomes. She told me she was making enough from female clients to supplement her student loan, but I suppose she wanted more because the last I saw she'd gone bi.
Lesbians aren't as easy as straight men so you're probably in a better position than the guys, but I haven't heard anything to suggest that you can make a living as a lesbian escort. If you want to try it as a side job and don't find an agency (or if you do and want to improve you chances), set up as an independent. This site already has just about all the information you need to do it, and if you have more questions you can ask. See if you can get a presence on local lesbian forums (even if they won't let you advertise, just being around and mentioning what you do so that people know you exist should help). I know a girl who booked someone who promoted herself in that way.