permeate (someone's) mind

Translations
проникать в (чей-то) разум
Doubt began to permeate her mind as she considered the decision.
Сомнение начало проникать в её разум, когда она обдумывала решение.
Definitions
To permeate someone's mind means to deeply influence or saturate their thoughts, beliefs, or consciousness with certain ideas, feelings, or concepts.