Hi and Welcome to the forum, you might want to have a look at the following FAQ which explains where everything is
Welcome to Benefits and Work In case you are not aware, your real name appears to be showing in the forum, if you want to change this then follow the instructions in the following FAQ
My full name is showing, how can I stop it?
These forms are new and we have not had time to see how DWP will treat them.
However, none of the descriptors have been changed since the benefit was introduced so it is logical to suppose that it will be 'safe' to tick 'no change'.
May I suggest that you bookmark/favourite this on your web browser now so that you can find it easily in future? This will allow you to return with further questions or comments relating to your wife's PIP without having to start a new topic each time. It helps us enormously when everything relating to the same claim is kept in one topic - and I hope you will find it useful too