Sometimes I think all you do is close controversial threads. But this indeed is the question to ask, IS IT REALLY SEVERE??? at 30 years old?
Assuming no coronary artery disease, same plan as 30y F w/o AS. Her BMI doesn't even start with 6, what's the big deal?
I'm not even joking. I've done this case in residency. 40F G12p11 with severe AS. Just have a phenylephrine drip and let the mom see the baby. Ended up doing her SAVR a few weeks later. Good case to reference for perspective. Her myocardium is strong enough to go through 9 months of this, I bet you in those 9 months she's valsalva, yelled, and screamed more times than you can count. This is as simple case of AS. Be diligent in replacing blood if they lose too much, she will do fine.
CSE with phenylephrine drip, continuous spinal if you want to get fancy and want to titrate.