Pregnant mare shots

My mare is going into her 7th month of pregnacy (first foal), I didn't know she was pregnant up until last month because she went into heat three times after I bred her back in April. Anyhow, she got her first rhino shot in her 6th month of pregnancy, should I wait until the ninth month or give her another one in her 8th month and then again in her 10th, since she never got one in her 3rd month? Also someone said that they need a tetnus shot in their 10th month, or do I do all the shots in her last couple weeks?
Also when should I stop riding her? I havn't been riding her hard for the past couple months, just bareback walk, trot, canter, and if not ridden lunged for a half hour. Should I slow down her workout?

Thank you!
-Britney-

The rhino shot (make sure it's the one for pregnant mares) needs to be given every two months. Since she got it in the 6th, do it again the 8th. I would imagine also the 10th, but ask your vet.
She'll need a booster of her regular vaccines, including tetanus, about 30 days prior to foaling to help the foal's immunity, so 10 months.

You can ride her as long as you and SHE feel up to it. Just keep in mind, the closer she gets, the bigger the belly! But you can hop on bareback and take her on a nice stroll even in the last month of pregnancy... just nothing too strenuous.

I appreciate your help! Thank you very much! :)

-Britney-