Call them (the numbers listed on their website). Depending on your specific circumstances they'll probably either update your wife's information for free over the phone or they'll charge you a £15 fee to uncheck the booking and you'll be able to do it yourself. The call is cheap and the staff are friendly and professional- not what most people expect.
Your defiinition of a cheap call and mine seem to be at odds. Ryanair charges anywhere from £0.10 - £1.00/minute from a UK landline (don't even think about the cost from a mobile
!) to talk to them. The good news is they only charge £0.05/minute to complain about the high call charges
.
Luckily you can call them direct in Dublin at much lower prices on +353 1 812 1212. Information from
SayNoTo0870