Thats definitely on the small side, but if the vet's ok with it and she's otherwise healthy and fit, then maybe she just is what she is!
What does the breeder say? How large are her littermates now?
MACH3 Bretta Lee Wildhaus MXG MJG MXF MFB TQX HIT CGC TC
Glory B Wildhaus AX, AXJ, XF
"Behind every great man is a woman rolling her eyes." - Jim Carrey