Thank you both for responding. The new Member advised me that she just left her old fs after tourney. That is when I tried sending invitation. I tried sending her invitation by going to her on list of all players, noted she left her FS, and expected to see "Invite Player" (forgot exact wording). I had this same issue in the past Ambassador.
Member acquisition was not checked and still isn't, but I was eventually allowed to accept her for membership from Aspirants.
Doesn't checking "Allow Members to send invite" box extend privilege of inviting new members to all member in fs. I thought privilege to invite new members was part of being a Mage and Ambassador.
I am not sure exactly what went wrong, but will try to figure it out next time we have an openning. Thanks for help.