You might post your request for info on the footstompin website, it is Scottish based and you should find more accurate and specific local info there, specially if you indicate your dates - --   Arran and Rothesay are both easily accessible from Glasgow by public transport (rail/bus then ferry) in fact in summer there is a choice of ferries to both islands, specially if you have a car but also by bus!) - I imagine Anne might wish to revisit Bute?

Meanwhile I shall contact the 'folkies' I know there, see if they remember her, mention she may visit in June.

if you are using public transport the traveline website is pretty good for finding various public transport - it does not always cover every possibility, local information (from tourist office etc) can be of more help.