Like you I am an "oldie but goodie"! and due to the age bias and ridiculous thinking about this, I have been writing, visited last July, was accepted and waiting to enter (after my house sells), with the Carmelite nuns of Kirk Edge, Sheffield, United Kingdom.
Their website: kirkedge.org.uk/index.html
Photos of St. Therese's relics that came to their monastery last October 1, 2009:
My own personal pictures I took (some from a friend who visited there also for her vocation) of my visit the Kirk Edge Carmel: s569.photobucket.com/albums/ss140/jmjtcarmelite/
At first I was sad to after to leave the US for follow my vocation to a good 1990, traditional, strict, austere, true to Our Holy Mother St. Teresa of Avila and her ideal for Carmel - in fact any Carmel that was even good - would accept my age and that I felt called to. So when I visited there, I was not only in peace and home, but in Heaven!
The majority of orders in the UK and Ireland either have no age limits or very high age limits. I know of Poor Clares and Poor Clare Colettines, the Carmels and Benedictines who do. Have no info on any Dominicans.
So for any woman serious about their vocation, up in age and feel called to Carmel especially and want to truly make a sacrifice of herself and all, then look over seas.
The UK only has 2 1990 Carmels, Kirk Edge and St. Helen's. The others wear the modified habit and are 1991s. One 1991, Wolverhampton, is full habit and very good though.
It's funny how the Carmels here in the US won't take older because the life is to hard or something, a Carmel like Kirk Edge which is much more austere, stricter and harder than the vast majority of the US will accept older vocations because with the vocation call comes the grace and the Mother Prioress there believes in giving all a chance if she believe they may have a vocation to come and try it. She says she is not about to tell God that SHE knows better in who to accept and turn away! This is not meaning ones who are totally unsuitable as in mental illness or a serious physical illness or other problem.
I had a wonderful PCC Abbess in this country tell me that for most orders, just as many young woman enter and leave as older women. It just depends on if it they have a true vocation, desire to stay, persevere, etc. Often this culture raises people to flee and give up when the tough gets going: marriages, jobs, etc.
Well, my 2 cents and more is over! lol!