I think you might be a but optimistic about how much money you would get for rent.
first of all there is inheritance tax. I know you say the house is worth £500,000 but no doubt your mother has other assets like cash in the bank or a pension. So the estate will have to pay 40% tax on some of it.
Then you and your sister will have to get the property up to legal standards for renting, perhaps put in a new kitchen and bathroom, redecorate, pay for landlords insurance and letting agency fees, which are about 12-15% of rent.
Tenants who are renting a property worth £500,000 will have high standards.
If you own the house 50:50 you will get the rent the same way and pay income tax on it. You need to save sone of the rental income for repairs and maintenance and any void periods or to cover rent arrears.
If either you or your sister have a job then the rental income might push you up into another tax bracket.
You and your sister will have to agree on everything that needs done to the house. As will your children and your neices / nephews / whoever inherits your share / your ex if you get divorced.
If you decide to sell it , you will need to pay capital gains tax on any increase in value .
TBH that’s a lot of hassle for everyone, potential to fall out . I would advise to sell it and buy your own place. there’s lots of tax breaks for owners that you wont get as a landlord.