。
She's stubborn.
Literal
She [topic-は] stubborn-person is.
意地っ張り ('stubborn, obstinate') is a fixed compound with the geminating っ + 張る ('to assert/insist') at its core — literally 'one who stretches/holds out their willfulness.' The double-meaning structure is typical: it functions both as a noun ('a stubborn person') and a な-adjective. In context, it often carries a half-fond, half-exasperated tone — admiration for grit mixed with frustration at inflexibility.