8 week old - starting to worry about weight gain

[Sleepstarved]

8 week old DD2 has only put on 7oz in last two weeks and has dropped from 50th at birth to below 25th.
lactaction consultant cut a posterior tongue tie last week but mentioned she has a high palate, upper lip tie and a white tongue still which she wants checked for thrush if not cleared (it hasn't).
DD is otherwise well, v smiley, cooing, trying to roll and seems v strong (excellent head control) but is unsettled at night.
Has one giant poo a day but plenty of wet ones.
Not seeing GP for 8 week check until gone 9 weeks cos of bank hol, should I go sooner?

What has the total weight gain been like since birth?
Neither of mine regained birth weight til after their tongue tie's were snipped. When can you next get her weighed? If weight gain improves post tie divide, I wouldn't worry.

If she looks dehydrated, I'd see someone ASAP tho.