She called me mate, I am losing interest

Maybe she's just a bit upset that you two didnt speak for 2 weeks? Maybe she thought you didn't like her that much, so she's being defensive by calling you mate - just a thought. If she's asking you to meet up with her, that's definitely a good sign - I'd go and see how things are in person.

I would probably act like this yeah. Bit defensive. Seems to me like she still wants to meet up so it doesn't necessarily mean she's not thinking about something else.

Everyones different.

I'm often matey with my prospective bfs. It's more a defence mechanism, protecting myself. I think my subconscious thought is if they're my friend they'll at least be careful with my feelings if they don't like me a bit more. I hate it when guys jump in at the first chance and start being too intimate. It's good to build that friendly connection first, enjoy each others company and if more does happen it's on solid ground.

Meet up and sus out what she's feeling. Don't dive in for a kiss or anything 'overly friendly' just a nice hug. Ask how she's been etc. See how it goes. If you're there and she's like 'mate mate mate' then she clearly is hinting and you should probably just ask her straight... 'You'll probably thinking I'm a little over the top but I'm just going to be honest with you...I noticed you kept calling me mate and we haven't talked for two weeks I was just wondering if I was right in thinking anything more than just friends is well off the the mark?'...