Hi Gogeter,
I have read your post with great interest and amusement. I don't often post only because I am so busy making the behind-the-scenes work here at the Café. However, I just have to join in on the fray here.
First, Shawn has offered you some sound advice. The first thing you need to do is to follow your heart. Halydia has also given excellent perspective.
Regarding the "variety of Spanish" you speak...it doesn't really matter since your job will be to teach English, NOT Spanish. I know plenty of English teachers who barely speak Spanish here in Madrid. So the mere fact that you want to learn ANY Spanish is admirable.
Who cares if the Spanish is Mexico is different from that of Spain? Most of it is just pronunciation/intonation and some vocabulary. It's not like they wouldn't understand you here. Besides, it's not like you will be speaking perfect "Mexican Spanish". You will have an accent. Don't sweat it.
Now, to address your greater question of being a mature female. Shawn is right own when he mentions that the older teachers are highly valued. The younger teachers are fine for some classes, but many of the business English classes will require someone who has had a bit more life experience and knows how to manage themselves in front of high level executives. That skill can only be obtained through professional life experience.
However, I’d like to be the counterweight here and play the devil’s advocate. It sounds like you are looking for stability. It is very rare that an academy will offer you a contrato fijo (permanent contract) outright. In fact, most academies work with contratos por obra y servicio (hours worked, hours paid) or contratos por prestación de servicios (where you are a freelance teacher offering your professional teaching services as a third party provider). The teaching English sector in Spain is an unstable sector to work in unless you have significant experience that may interest a school or university to employ you full time. Many academies and consulting agencies have gone out of business over the past couple of years due to the economic crisis that is currently thrashing Spain.
Adding insult to injury, Spanish law allows businesses to pay 90 days after billing. So, if you are working as a freelance teacher and work directly for a company teaching English, the company may take as long as 3 months to pay you. This is also a difficult situation for many academies since few of them have the capital necessary to float/pay a team of teachers for three months while they are waiting to get paid from the client. It’s a tough situation all the way around.
Added to that, the unemployment here is high…at 20% if not higher. So, private classes are drying up and those that do exist are being competed for by the overabundance of English teachers already here.
I don’t want to dishearten you, but I do think you need to have a balanced view of what is really happening here now. Shawn is in a great position because he has been here for years, has built up a reputation and a solid client base. Halydia is also in a good position because she is here working in a public school and because of her visa status, can work legally for academies pushing the “illegal” teachers (those without the proper work/student visa) to depend solely on private classes to get by. For those making the move to come over now, the situation is a bit different and perhaps much more challenging.
If you are one who believes firmly in your dreams and knows how to make opportunities (not just expect them to happen) you will be fine wherever you end up…as long as you know what to expect.
Good luck with your decision!!
-R