While I am still in the process of joining as a DEO reservist, I do know someone who has been in the army for several years (is over 30) and is switching to nursing as an officer next year. She is excited about it. While I naturally defer to the CF veterans on here my 2 cents would be that it's up to you (and your family) to decide what's best for you. There are many people like myself who are not in their twenties anymore but more than happy to do something they wish they had done 10 years ago.
I personally wouldn't want to be in my 40's or 50's wishing I had joined up at 30. So think about it, if you don't do this now, are you going to look back in 10 - 20 years and kick yourself for not at least trying it. After all, you can always go back to civilian nursing, albeit with additional leadership training and experience.
In regard to your concerns - "bit worried that I might be a bit old to do the program cause anyone I talked to about it said that I should have do it in my 20s, its too late, blah…Plus the wife is worried about finances, accommodations etc…" I would sketch out a tentative 3 year plan to account for training, how much you'll make and so on so you can see real figures and get a clear sense of what you're getting into.
Another option would be the reserves, where you would still have your higher paying job initially, and then maybe when fully qualified or higher in rank you could consider going reg force. Best of luck to you.