my wife's iphone 4s cannot invite invitees from the calender, message is not being sent to invitees, help please

If some one kind enough could respond please would be much appreciated, i think i have tried all kinds of troubleshoots.

Let me explain again what the problem is.

in calender lets us add an event no problem time dates location etc... when you get to invitees we enter my email address as my wife wants to invite me, but after clicking done, the phone only alerts her phone but not mine.

awaiting a reply, thanking you in advance

aip3