Shield-maidening

"Shield-maidening" is a derogatory term that describes when a woman unnecessarily defends a man to gain favor or attention sexually or non-sexually. It can range from her defending/protecting and/or affirming a man's physique, intelligence, dating preference, etc. where it is unwarranted.
This term is the female version of the term "White-Knighting."

I saw this woman shield-maidening a guy online who stated he deserved a supermodel rather than an average woman when other people disagreed with his shallow opinion.

Stop shield-maidening that dude! You're giving them damaging advice!

Oh boy, some chick is shield-maidening.