Thank you for taking the time to post on the forum in relation to your daughters new SIM. We can understand the concern and confusion caused.
Is this something you still require assistance with? If so, please let us know below and we'll be happy to help further.
A few things to check first, is the handset the SIM has been tried in unlocked? For example, if you get a phone and a SIM from a provider the handset will be initially unlocked and open to all providers. Once a SIM card is inserted and a connection made to that network the handset then becomes locked to that network.
If the handset was purchased or used with the Plus Net SIM it may need to be unlocked form that network.