Sponsoring a parent takes a long time. Just to approve the sponsor takes right now 32 months, see
http://www.cic.gc.ca/english/information/times/canada/process-in.asp#sponsorshipThen the file goes to Egypt and takes there on average another 13 months, see
http://www.cic.gc.ca/english/information/times/international/08-fc-parents.asp#africaTo be able to start sponsorship of your mother, you need to prove that you make enough money to support her as well as your own family. For yourself, your wife, son, daughter, mom, 5 people, you need $45,662 per year. If you reach this income in less than a year and can prove that with pay slips, you can start sponsorship or you wait until you do your taxes and get your tax papers back. If your wife works and you want to count her income as well, she can co-sign. You will be responsible for your mother for 10 years after she gets her PR. If she goes on social assistance, you pay.
Your mother can not sponsor your sister because she is an adult, not a dependent child. Best way for your sister if she is an accountant is to apply herself as a skilled worker. She will be in Canada before your mother will.
The only way you or your mother could sponsor your sister would be if you are in a province which as a family stream program under their provincial nominee program and both of you qualify. All of them have slightly different requirements but you would have to live in that province as a PR for a year or two before you could sponsor. There might however be problems if you try to sponsor them both at the same time.