I would give less until you can speak to your DN as I have been on both insulins and needed far less of the Glargine than I did of the Levimer, my DN said the Glargine is beefier than the Levimer so less is needed ( i was on 40 units of Levimer but only needed 22 units of Glargine) its far safer to be a bit high for a few days until you can get to speak to someone than have serious hypos and you can always give a little bit more short acting in the morning if high. You say that she is going back on the Glargine .... if thats the case I'd start off on the dose she was on when on the Glargine until you can seek help