Alice prefers men who are even stronger than she is, but only if they also have other positive characteristics, such as kindness.
Alternatively; Alice prefers men who are stronger than her, but is willing to go out with a guy who is weaker than her if he has a positive characteristic like intelligence or compassion to make up for his lack of strength.
Alice wants a man who is equal to her in strength.
Tough chick Alice is worried that No Guy Wants an Amazon, but compared to the hulking man-mountain that is Bob, she's positively dainty, so that won't be a problem.
Alice comes from a society of Amazons who praise strength, and finding a man who can hold his own against them is a rare occurrence.
Alice doesn't want a boyfriend she could accidentally injure.
Alice, being an Action Girl, gets into a lot of fights and wants someone who is able to protect her just in case she is unable to do the job herself.
..At least, that's what she says, but she's just not ready to admit her true feelings.
Then he learns some martial arts & becomes a better fighter than Alice and made her find him more attractive.
Alice is also attracted to males who are stronger than her as well as females.
Alice acts as if she doesn't care to avoid hurting Bob's feelings or looking shallow. She's really disappointed about Bob being weaker than she previously thought.
Parodied: Alice goes from no-nonsense warrior chick to fawning blob of Squee at the mere sight of uber-manly hero Bob.
Zig Zagged: Alice has an open and obvious crush on Bob because she admires his strength, and she just as publicly looks down on Morris for his presumed weakness, but deep down she cares more for Morris because she feels more comfortable around him and they complement each other's personalities. She refuses to admit this to herself, however.
Averted: Alice doesn't care how strong Bob is. She's more concerned about how compatible they are personality-wise.
Lampshaded: Charlie, who's thin and scrawny, complains that Alice only loves Bob for his muscles.
Invoked: Alice figures that with Bob's huge ego, he'd be annoyed if she made him feel inferior with her muscles, so she tells him he'll have to work out for a long time before she even considers dating him.
Defied: Alice refuses to be with any man who's stronger than her.
Conversed: "Oh, of course the writers paired those two up. She's strong, he's strong. Predictable, as always."
Deconstructed: It turns out that Alice is strong because she's good at tactics and Bob is strong because... He's a pile of meat. Alice quickly dumps Bob to hook up with Morris, the Smart Guy.
Played For Laughs: The entire Amazon's tribe goes crazy over Bob, so they start a hilariously violent civil war to decide who keeps him, much to Bob's chagrin because he's not interested in women, at all!