Well…yes and no. I mean, if all she did was delete from photos, songs, or whatever, then no, that won’t help. She’ll have to do a couple extra steps.
Most Android phones (the exception being a couple of the newest ones running Android 4.X) have two completely separate internal storage spaces. There’s the App Storage, and then there’s the SD storage, which despite being called SD storage, is actually a combo of both an internal storage (but not the internal app storage) and the SD card storage.
Manufacturers, especially on cheaper phones, skimp on the internal app storage space. I’m guessing that she only has 250 MB of app space…by contrast, mid-to high level phones have 500 GB to 1 GB.
But there is a way for her to free up more app storage by moving some of her apps to the SD card storage. Not all apps can be moved to the SD storage, and even some of the ones that can you shouldn’t (any app that has a widget, for example, shouldn’t go to the SD storage.)
To do this, she has to get into her Application Settings.
Menu->Settings->Applications->Manage Applications.
Then, at the top, she should click “All.” She now has a full list of all the apps on her phone, and the space each one is taking up should be listed right below the app. If she then click on an app, she’ll go to a page will all the details for the app, as well as options like “Force Stop,” “Uninstall,” “Clear Data,” and “Move to SD Card”
In case you can’t tell, that third option is the one she should choose for large apps. IIRC, the G+ app is fully capable of being moved to the SD card, and also fairly large (I think over 20 MB.)
She should go through the list and not only uninstall apps she never uses (plenty of phones come pre-installed with near-useless apps, though unfortunately many of them can’t be uninstalled unless she “roots” her phone, which we won’t get into here,) but move the larger apps that let her to the SD card (again, any app that she uses a widget for she she leave on the app storage.)