Jan, if you select the txt and look at your layers panel and see txt as type then all you do is select the word and then the Aa in the right hand panel and the font used appears. If the letters have be connected via union or trace then all you can do I think is get a screen grab of the word and go to whatsdafont.
I find it useful to put project info like font used in window/project info where I can find it later. I also use this space for info on where the image came from
Maybe someone will come along with a better answer
LEARN, GROW, CREATE, SHARE
Mac 10.9.5 Yosemite, eCAL 1.506, ECAL2.023, SCAL4Pro, Export Plug-in, Inkscape 48, iPad/scal3