Would my spouse and I be able to use them by just putting our SIM cards in those phones or will those phones be locked into the Orange network? If they are locked in, is there anyway of unlocking them?
If the phones were part of a "pay as you go" rather than monthly contract package then chances are they are locked to the original network. If a certain amount of credit (varies but c. €125 would be in or around standard in Ireland) has been bought for them over the period of ownership (allowing the provider to recoup the cost of any handset subsidy) then the service provider will normally unlock them for free. Otherwise they may charge a fee. Alternatively independent third parties, some of them legitimate some of them possibly not, may be able to unlock them or you may be able to get unlocking codes or software by searching the web. There is also a possibility that the phones are also locked to the original SIM in which case unlocking in this respect will also be required. Once the phones are unlocked they should be usable on any network.