Is the probability of heads now 1/100 from SB's point of view?
The operative words being "from SB's point of view".
She doesn't know if this is her first or 69th awakening. All she knows is she is awake and there are 99 ways for that to happen if the coin was tails and only one way for that to happen if the coin was heads. Yeah, 99 to 1 for tails. In her mind, flipping a heads is the least probable event explaining her being awake.
Interesting.
Stop Tzar Vladimir the Condemned!