。
When she smiles, adorable dimples appear.
Literal
She [topic-は] laughs [when-と] adorably dimples appear.
The conditional と marks an automatic, reliable consequence: whenever she smiles, dimples form. えくぼ (靨, 'dimples') is typically written in hiragana. 愛らしく (あいらしく, 'adorably, charmingly') modifies the dimple formation with a warm, affectionate tone. できる here means 'to form, to appear' — a different sense from 'can do.'