Is this normal? Should I worry?

At 8 months my daughter first bottom tooth came in. At 11 months another one started and then as it grew (from my own research) it seems to be a germinated tooth because it has two "heads".

Thus far this is all she has.

Everything I read, this isn't normal.

I read, it should have came in pairs, together at the same time.

And that every month after the first tooth she should have gotten another one. But she hasn't.

What was the timeline of your baby's teeth?