Hello I’m a 15 year old flying from iad to lhr next month in ba first however my mum and dad is in economy as a perk of ba first you can have one guest but with ba lounges you have to be over 18 to enter or have an adult my question is would I be able to guest my mum in to the first lounge and be considered my responsible adult or will they say no as she would need a Club world or first ticket

Thanks in advance