。
She loves her children.
Literal
She [topic-は] children [object-を] is-loving.
愛する ('to love') is the formal verb of love in Japanese — closer to the heavy English 'love' than the more casual 好き ('like / love'). Almost always appears in the ~ている form (愛している) when describing an ongoing love, since it's understood as a state rather than a momentary action. Note how subdued 愛する feels in everyday Japanese: speakers often prefer 好き or 大好き for declarations of love. 愛している as a romantic confession (to a partner) sounds quite serious or even literary.