My mom is have a 3cm lesion from her skull removed tomorrow. what will recovery be like and for how long? she will have craniotomy with titanium

Craniotomy: The recovery time varies from 1 to 4 weeks depending on the underlying disease being treated and your general health. Full recovery may take up to 8 weeks.

Relatively easy: Recovery from the operation - discomfort for a week or two, until sutures/staples come out. Recovery from anesthesia and intubation - depends on mom's overall health status but should be fairly quick. The nature of the lesion (benign or not) will determine the overall outcome.