i think it's totally subjective and you have to ask yourself wheter you need it or not.What do you like about having both platforms? Do you just enjoy being able to use different apps for both, or do you find having the mix to be particularly effective for what you need to do? If the latter, how so?
I don't even understand (sorry if I misread or failed to read for that matter) if you already have an iPad.
Android and iOS both can play well, but then for ME it would have to be somehow this way:
1. If using the same apps, then they should be synched over the cloud with something DIFFERENT than iCloud (which is not hard enough, e.g Evernote).
2. I would have to be comfortable using the *smaller* version of apps on whatever I choose.
For me basically (2) was the deal breaker with my old android phone, I couldn't stand it anymore and there were some apps (specially productivity and music production) that weren't available on Android (specially the latter), and I saw myself using my iPod Touch more and more, so I decided to go the iPhone/iPad combo and couldn't be happier.
Now this is obvious trolling
Because there are apps available on iPad and NOT on iPhone and sometimes you use an app on the go (small screen, small keyboard) and then at home you can have the same info but on a bigger screen, and without turning on your desktop computer and in the comfort of your couch.why would you want an iphone to go with an ipad? They're the same exact thing. One is just 10 inches and doesn't do calling
Plus the iPad has been proven a good replacement for a laptop, in some cases.
So yeah, in the long run it's all about the screen state but they are NOT the same thing, unless of course you like carrying around a 10" cellphone OR you like writing books on a 3.x" screen (yes, the iPad is not a cellphone, but point made hopefully).
So far I think your wife would be happy wth an Android phone, specially the music (copy & paste, don't quote me about the ratings and stuff tho) and more flexibility.
Problem being, she has an iPad already and I think the perfect combo for an Android phone would be an.. Android tablet.
I personally decided iOS because although it's a bit "boring" (no widgets basically and bad theming), I think the apps I use look much better than Android (apps I tried and use looked cheesy and disgusting, others might say au contraire) and the iCloud and general syncing between the two was great.
Plus, music production (on a low scale) is on the iPad a billion? trillon? times better than Android where it's almost non-existant (so far).