Who is Manitoba's provincial representative?

There is no such position as Provincial Representative. The chief executive and representative of the Queen within the province is the Lieutenant Governor, his Honour the Honourable Philip S. Lee. The head of government of the province is the Premier, the Honourable Greg Selinger. He is a member of the Legislative Assembly of Manitoba, as well as of the Executive Council, which is made up of ministers responsible for various aspects of the Government of Manitoba. There are 56 members of the Legislative Assembly of Manitoba, each of whom represent a riding within the province.
At the federal level, Manitoba is entitled to 6 Senators in the Senate of Canada, and 14 Members of Parliament in the House of Commons. The province is represented by the Premier at First Ministers' conferences and in the Council of the Federation. The minister of intergovernmental affairs is responsible for the province's relations with other provinces and with the federal government, as well as, to a certain extent, the province's foreign interests.