Tony, thank you very much for the hint.
A finger force of 70 Newton corresponds roughly to 7 kilograms. Double this even more roughly and you get 14 lbf. The exact value is 15.7 lbf. I could have checked it easily that the '300 lbf' were wrong. I'm sorry. The woman's finger force of 50 Newton corresponds to 11.2 lbf.
Ulrich