Applying my GF and 17yrold Cousin for visitor's visa

[flat21]

I have a GF (age 24) in Philippines and next year we plan on inviting her to visit the UK for only 6 weeks along with my 17 year old cousin, the plan is to have my mother sponsore their travel and accomodation while visiting the UK. My mother is a british citizen while I have a ILR visa, we though that having my mother sponsor them (instead of me) would increase the chances of them getting approved. We plan on having them apply for a Standard Visitor visa and their visit will be during school break, my cousin is still a student while my GF is a full time teacher and the plan is to have them return to Philippines before school restarts on June.

I have written an invitation letter stating that my GF is a "family friend" rather than stating our actual relationship, im wondering if this would this be a good idea or is there a better most reliable way for my GF and cousin to get approved? Any advice would be appriciated.

[flat21]

My parents and I are planning to sponsor my GF(24yrs) and my cousin(17yrs) to visit the UK for 1 month from Pihlippines. I would like to ask if both person will have to have visa application done individually?
Im asking this question because during i was processing my GF's and Cousin's application, there was a section "About the person travelling with you" on my gf's application which i only needed to mention my Cousin's name,nationality and relationshop to her. On the otherhand, my cousin's application from that same section has Child traveller "How many adults do you want to list on your visa?", since my cousin will be travelling with my GF, does it mean that my GF is includen on her application already? thus i am not required to apply my gf's individual visa?

[CR001]

I would like to ask if both person will have to have visa application done individually?

2 separate applications and each must submit their own evidence of strong ties to home country.