Then Sally's shrink spurts were starting to speed up. She shrank another 40 feet. Now she was less than half her original size.
"I shrank again," said Sally. "Am I just going to keep shrinking until I'm nothing?"
"Well I hope not," replied David. "I like my girlfriend to be the size of a mountain not an atom."
"Thanks for that." Then she looses another 50 feet. Now she is only 20 feet. "When will it end?" Then she shrinks down until she's the same height as David.

What happens?