As far as I know you can install Lightroom on multiple devices.
But there is a limit on the number of active devices, I think you can have max 2 active devices.
As long as you work alone with the software it is no issue.
But I think it will be an issue if you, your wife and the three kids will work at the same time.
It depends on which type of plan you subscribe to. My assumption here is that the OP has subscribed to the mobile premium plan, which does not include the desktop version of Lightroom.....and it is only the desktop app which has the 2 activation limit. Mobile usage is unrestricted in terms of device numbers, the only thing I'm not certain about (which is the OP's question) is whether paying for a premium plan via the Apple Store or the Google Play Store allows the mobile app to be used unrestricted on both iOS and Android devices. I would have thought so, but I'm not 100% certain.
Subscribing to Lightroom on your phone gives you access on all iOS and Android devices, but not on your desktop computer. If you need LR on your desktop too, please cancel your iOS subscription, and subscribe via the desktop app instead. LR desktop plans do cost more but come with much more storage and do include Lightroom Mobile access. LR desktop plan options info: https://www.adobe.com/products/photoshop-lightroom/compare-plans.html