No you cannot bring your mother in law to the UK to be your servant.
http://www.ukba.homeoffice.gov.uk/sitec ... nges-rules
Overseas domestic workers
Restricting all overseas domestic workers (ODW) to only work for the employer with whom they entered the UK, or whom they came to join.
Removing the right for all migrants under the ODW category to apply for settlement.
Strengthening the requirement for the employer of an ODW to provide evidence of an existing employer relationship, and introducing a requirement for agreed, written terms and conditions of employment to be produced, as part of the application for entry clearance.
Permitting all ODWs who have applied for leave to enter or remain on or before 5 April 2012, to continue to be treated under Immigration Rules in place on that date.
Restricting ODWs in private households to work for an employer who is a visitor to the UK. Permission to stay in the UK will be limited to a maximum of 6 months or the period of the employer's stay whichever is shorter. Removing the current provision for ODWs to be accompanied by dependants.
Permitting ODWs in diplomatic households to apply to extend their stay for 12 months at a time up to a maximum of 5 years, or the length of the diplomat's posting, whichever is shorter.