Looking on the internet deeply has found these results:

she is pretty is the most popular phrase on the web.

she is beautiful 156,700,000 results on the web	she is pretty 187,600,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
She is beautiful as sweet as honey She seemed nice enough, and she is beautiful. And she is beautiful, with a... a facial expression just like his daughters'. Who knows what could happen She is beautiful You know? She is beautiful when she's not about to throw up. She is beautiful, clean and has good manners. She is beautiful, proud, sensuous. And, kid, she is beautiful.	SW: Very good. Now, really, she is pretty nervous. I mean, from what we've seen, she is pretty good at multitasking. Berke, she is pretty. Because... she is pretty and smart, and when you talk about work, she doesn't have to go home and look up words in the dictionary to understand what you said. Yes, she is pretty. She is handsome, she is pretty She is the belle of Belfast city Then again, she is pretty hot. I choose you, baby. She is pretty, smart and her family is rich.

she is beautiful

156,700,000 results on the web

she is pretty

187,600,000 results on the web

More popular!

SW: Very good. Now, really, she is pretty nervous.
I mean, from what we've seen, she is pretty good at multitasking.
Berke, she is pretty.
Because... she is pretty and smart, and when you talk about work, she doesn't have to go home and look up words in the dictionary to understand what you said.
Yes, she is pretty.
She is handsome, she is pretty She is the belle of Belfast city
Then again, she is pretty hot. I choose you, baby.
She is pretty, smart and her family is rich.