Joint members but only one can book

Forgive me if I have miunderstood how this works but some guidance would be welcome.

We are very new members, only joined last year when we bought our first motorhome. We must have got hooked because we have just traded it in for a newer one.

We signed up to joint membership. Now, I think the word 'joint' should mean that both of us have equal priveleges. However, we have discovered that only I, as the lead member, can book CC sites via the website as only I have a login. My wife cannot book a site without using my login. While I don't have a problem with that it seems somewhat unfair. 

Surely a couple with joint membership should have equal access.