Although born in Portsmouth, Holden spent much of her childhood in Bishop's Waltham and aged 9 she joined Bishop’s Waltham Little Theatre Company.
Meskipun dilahirkan di Portsmouth, Holden menghabiskan sebagian besar masa kecilnya di Bishop's Waltham dan pada usia 9 ia bergabung dengan Perusahaan Teater Kecil Waltham milik Bishop.