If there's no server, a woman can make the responses and ring the bell from outside the sanctuary.
Why not in sanctuary?
Any woman who would want to serve in the Sanctuary during Mass (or worse, presume that she has some kind of "right" to do so) is exactly the kind who should stay furthest away. She should pray and do penance and ask God for an increase in humility.
Look at some of the women in the pews at the TLM - praying in holy, pious silence; their heads covered and their clothing suitably modest and feminine. Then look at some of the short haired, bare headed, pants wearing, haughtily mannish "Madame Lectresses" (as Fr Hesse used to call them) casually traipsing about in the Sanctuary at any given Novus Ordo parish. Which is the better example of Catholic womanhood?Let women keep silence in the churches: for it is not permitted them to speak, but to be subject, as also the law saith.
1 Corinthians 14:34