You cannot use your mother’s country of birth to qualify for the lottery as individuals born in the Philippines are also disqualified from participating in the lottery.
As for your father, what UK immigration status did he have when you were born? If he was a UK resident or citizen, you cannot use Mauritius to qualify for the lottery. In order to do so he would have had to be only visiting the UK temporarily at the time of your birth.
If you believe you qualify, please visit my website for more information about the lottery application process:
http://www.immigration-aux-usa.com/Green_Card_USA.html