彼女は何度も納期を守れなかった事がある

There were several instances when she failed to meet our deadlines.


⚫︎〜だったことがある

There were an instance when...


⚫︎someとseveral

ぼやっと→some

具体的に例を言える→several


⚫︎didn'tとfailed to

事実報告→didn't

残念、懸念(気持ち強調)→failed to


⚫︎納期(締切日)に間に合わす

meet deadline(s)

※何度も納期に間に合わなかった→deadlines