After I wrote the above I thought, is fiberglass stronger than human bones so I asked and the AI "DuckAssist" said.
DuckAssist
BETA
"Fiberglass can be very strong, with some types reaching tensile strengths of up to 2,358 MPa, which can be comparable to or even exceed the strength of human bones. However, the specific strength can vary depending on the type of fiberglass and its construction."