Hypothyroidism and pregnency. Please.

Good morning sir/Mam,my friend has been diagnosed with hypothyroidism and started medication from April 2021 till today with a dose of 50mg.now by November 28th her pregnency was confirmed through testing kit and when we went for a check up this Monday (Dec 19th)was asked to taken blood tests including TSH ,and received mu reports yesterday in which my TSH level was 5.01.since my friend's in laws don't know that she has hypothyroidism she couldn't say to doctor that she is already consuming eltroxin50mg.so the doctor suggested  a 50mg dose of eltroxin now thinking that this is her first result with hypothyroidism. So can any of practo's doctor help me with this situation that what should be the correct dose for my friend please.