、。
I love her, and she loves me.
Literal
I [topic-は] her [object-を] love-[state-contracted-てる]-[and-し], she-[also-も] me [object-を] love-[polite].
愛する ('to love') is a fairly literary/dramatic verb; in everyday Japanese, 好き is far more common for romantic feelings. The inconsistent politeness registers between the two clauses (casual 愛してる + polite 愛してます) is slightly unusual — possibly the speaker switches tone for emotional emphasis. ~し links clauses with a reasoning/coordinating sense.