"Do matčina pokoje nikdy nechodím."

[dsarkarati]

"I never go into my mother's room." is correct and should be accepted. Its meaning is identical to the given translation.

[dsarkarati]

"Going into a room" is identical to "going in a room".

[Hugo647250]

And, IMHO, "into" rather than "in" sounds more colloquial at least for USA English usage.