Collins online French / English https://www.collinsdictionary.com/dictionary/english-french (and use the built-in browser tools to zoom etc if required). If you have access to Google Chrome browser the ‘SpeakIt’ extension will read aloud highlighted words and sentences – there are European French male and female voices for free.
Franklin Bilingual French / English Electronic Dictionary: http://amzn.eu/axB7FHh (screen might be a bit small but there are speaking ones too).
Lingoes (free): http://www.lingoes.net/ you can download Lingoes (with a French dictionary) as a portable option so the pupil can use it on a USB pen drive, no installation required. There are options to increase text/font and general interface size etc. Easy to use.
Penfriend XL – http://www.penfriend.biz/pf-xl.html word prediction in French and runs from a USB drive.