She looks like me and her behavior is also likes me. She looks like me and her behavior is also like me.

She looks and behaves like meの方がネイティブ

She looks like me and her behaviour is also likes me. She looks like me and her behaviour is also like me.

She looks like me and her behavior is alsoacts likes me, too. She looks like me and acts like me, too.

So to fix the grammar, we can just say "her behavior is also like mine." However, I tried to make this a little more natural.

She looks like me and sher behavior is also acts likes me. She looks like me and she also acts like me.

I won’t leave her by herself because she’s my treasure. I won’t leave her by herself because she’s my treasure.

Alternative: I won't ever abandon her because she is my treasure.

I won’t leave her by herselfalone because she’s my treasure. I won’t leave her alone because she’s my treasure.

Another way you could say it is 'I'll always be by her side because she's my treasure.'

I won’t leave her by herself because she’s my treasure. I won’t leave her by herself because she’s my treasure.

This is OK, but to me it sounds a little better to leave out "by herself." Saying “leave <a person>" by itself captures what you are trying to say.