Holly from Big Brother’s age depends on which version of the show you mean, as there are several contestants named Holly across different years and countries. If you’re asking about a recent Big Brother Australia contestant named Holly Young:

• Reports identify Holly Young as a 31-year-old model from Western Australia who joined the 2025 season. This is the most current public information circulating about that specific “Holly” in Big Brother Australia 2025.

If you meant a different Holly:

• The name appears in multiple Big Brother franchises and earlier seasons (e.g., different countries and years). Ages and biographical details vary by season and nationality, so specifying the exact version you’re watching (e.g., country and year) will yield a precise age. For example, older American or other international editions feature various contestants named Holly with different ages.

Direct answer for the most current context you provided:

• Holly Young in Big Brother Australia 2025 is reported as 31 years old.