I too am a yoga teacher with a strong practice...I have had the surgery and am back to my full practice! So yes, you can get back to a good strong and intense practice after the dr. gives you the ok to exercise..just know it will take time and your body will be different so your practice will be different...if you want more yoga detail...please feel free to pm me! :)
Do you know if you had the top of your vagina supported when you had your hysterectomy? If you didnt then it is more likely that this is one of the reasons you have further prolapse and since you dont mention what POP you have I guess you likely have vaginal vault prolapse although this may not be the only POP you have.
You will have a few weeks running into around 3 months of healing to do and with you getting more active within this period after your op. Yoga is normally seen to be a good exercise to do when you have POP and even after healing fully from a POP op but no positions that increase abdominal pressure are seen as advisable as these will put pressure on your op site etc., For example, planking or stomach crunches are out. It could be helpful for your yoga clients as well as yourself to get fully versed on what is and isn't contraindicated for ladies pre or post op with yoga as you will have a more comprehensive way of teaching your clients as well as helping yourself.
Give yourself a full 12 weeks before you go back to any full routine and listen to your body.
As far as your flight attendant job is concerned dont go back to early to this job and lifting is also contraindicated so you may need to consider how much you lift in this job as well.
Are you having a Urogynecologist do your operation? they are POP specialists. Ask them as well as to their advise. Some Drs seem to give a short 6 week healing period as advised but most POP ladies need double that in time to feel they are able to function near normal.
Can you consider teaching your yoga students some of the moves without doing them yourself? Knowing more about POP could help you to be even more comprehensive in your yoga teaching and may well have helped you to to be able to stay on your feet more with mindful movement and attention to your core so you could already have reaped some of the benefits of your yoga training and be able to help others as well with your teaching.
Good luck with your operation and let us know how you get on.