Yoga

I will be in Paris for two weeks in April - May. My apartment is in the Marais area. I'd like to take a yoga class or two during my stay. Can anyone suggest a studio with drop in classes that would be welcoming to a beginner to medium level yogini? I have been taking yoga for years, but still consider myself at the lower level. Also, I am 61 and would like a place that is open to a fit older woman practicing without judgment. Thank you in advance.