Help her??

My neighbour asked me give a hand in by tuition with her daughter who just standard 6...I agree.And tuition subjects are all language subject which i also quite weak in...Oh my god...She required for three days tuition,that is from friday until sunday..Mean i have to back home from upm on thursday night and keep teaching..After consideration,i decide to shorter the tuition to two days..I asked my mum tell the aunty as she always meet the aunty..What i get from my mum is she said she very disappointed with her daughter's result..Hope i can help her and her daughter..But,i have to back upm on sunday..There will be a rush for me if the tuition remain three days..What should i do? If she talk like begging me sure will soften my heart later. The tuition is starting by tonight..How ??I should remain for two days..please...