If she's doing "headstands" in her tank, please DO post pics, LOL! Sorry, but I had to ask about the location of the bulb, & not "assume"...we never know.

So this pink "tail-end" has only been a recent change? Does her tail seem swollen at all? What is your actual humidity reading IN the tank? (heat does dry it out,
even when you spray & local natural humidity is high)