Emberton, who uses the Northern line to get to work, said she walked to the front of the platform in the hope of getting a seat on a quieter carriage, and waited for busier trains to pass before she boarded.
“I can count on one hand the number of times people have got up and offered me a seat,” she said.
Emberton said it was not an issue limited to priority seats, designed for people who are disabled, pregnant or less able to stand, but throughout the entire carriage.
“Those on normal seats could offer up their seat,” she added.
The mother-to-be said she did not feel comfortable directly asking people to give up their seat for her.
“I feel anxious about asking someone to give up their seat as I worry it will be met with frustration,” she said.