I would be very careful here. First, you do not know if HR is working with this nurse regarding any physical limitations she may have to performing certain job functions, if she is under workman's comp., etc. Also, if you decide to document and take your grievances up the appropriate chain of command, be sure to focus on the facts of what was asked of her and the reason given for declining to help; do not bring age into the documentation. Age is not and should not be the issue. Job performance is the issue. Hope that is helpful! Good luck!