Why does my girlfriend call me silly and cute?

I have never been in love before until I met my girlfriend, now almost one year ago.
The relationship is going well, and as far as I can tell, we're both very happy.
Sometimes I wonder though.
Honestly, both my girlfriend and I have little to no experience when it comes to dating, because we've both been odd ones out our entire lives.
so sorry for maybe asking a question everybody might know the answer to already lol.
But she often calls me silly, whenever I compliment her.
I find her beautiful, but she always kind of seems to be doubtful when it comes to me complimenting her about her appearance.
She'll just hide her face, and look away, Or she'll laugh.
Also, I am a very shy person generally,
and whenever I am she seems to be able to smell it from miles away lol.
And she'll call me cute. Is there any particular reason for her saying these things?
What does it mean when she calls me cute and/ or silly?
Thanks in advance.

She does not believe she is a beautiful girl and might also assume you couldn't possibly find her very beautiful. So she calls you silly for saying that she is beautiful, rather than accepting the complement. However, she likes the compliment, so keep reminding her that she is a beautiful person :-)

And calling you cute is good thing, even though it does not sound as a very manly complement haha

Cheers!