|got an oval face with bright blue eyes and a big smiling mouth.---In English, saying someone has a big mouth means they talk too much! :-)
She has long, brown, wavy hair, but she usually wears it in a ponytail. She is quite beautiful, especially when she smiles.
She always seems to be ...
.. what fits me and what does not.
We are really close to each other; she can tell if I'm lying even if I am keeping a straight face! I don't know how she does it! These sentences are very well-writen.
I don't know how it is possible, but I am never bored with her.
Sometimes she tends to be stubborn; she never admits her faults. She is stubborn only with her parents, though. She and I have never argued.
Nice job!! I like it.