A partial tooth

I think Fiona's bottom right tooth broke through her gums sometime late last week.  I felt it this past weekend, but can't see it yet.  And for some reason Fiona doesn't like me messing with her lips and gums.  I guess I can't blame her, I wouldn't like that either.  So does that count as her first tooth or should I be able to see it?  This is a new experience for me also as I don't remember my own first tooth.  Does it just pop through or does it progress slowly (like fingernails)?