、。
She tried several times, but failed.
Literal
She [topic-は] how-many-times-か tried [but-が], failed.
何度か uses the か variant of the 何 + counter pattern: where ~も gives 'many,' ~か gives 'a few, several' with a faintly more bounded, less emphatic feel. 試みる ('try, attempt') is a slightly literary variant of 試す ('try out'); both work, but 試みる leans toward writing and serious attempts. The trailing が is the contrastive 'but,' setting up the deflating 失敗した ('failed') — a clean two-clause story arc in one sentence.