How do you persuade your parents to let your best friend come round? MY BIRTHDAY TODAY♥!?

Basically its MY BIRTHDAY TODAY and i really miss my bestfriend niamh, i want her to come round but i dont really know how to ask my parents really? sounds stupid but my mum is a bit stressed at the moment because she came out of hospital about 6 days ago.. how should i ask her? PLEASE HELP ME♥♥