I think I got it now
SELECT People_tbl.[Parent ID], People_tbl.FirstName, People_tbl.LastName, People_tbl.Weekly, People_tbl.Month, People_tbl.ServiceArea,
People_tbl.ReferralStatus, People_tbl.ScairCaseWorker, People_tbl.TANF, People_tbl.Adult_Child, People_tbl.Manzanita, TanfActivity_tbl.EventDate,
Counselors_tbl.CounselorsName, Counselors_tbl.Counselor, Counselors_tbl.CounselorID, Counselors_tbl.EffectiveDate
FROM People_tbl INNER JOIN
TanfActivity_tbl ON People_tbl.[Parent ID] = TanfActivity_tbl.[Parent ID] LEFT OUTER JOIN
Counselors_tbl ON People_tbl.[Parent ID] = Counselors_tbl.[Parent ID]
GROUP BY People_tbl.[Parent ID], People_tbl.FirstName, People_tbl.LastName, People_tbl.Weekly, People_tbl.Month, People_tbl.ServiceArea,
People_tbl.ReferralStatus, People_tbl.ScairCaseWorker, People_tbl.TANF, People_tbl.Adult_Child, People_tbl.Manzanita, TanfActivity_tbl.EventDate,
Counselors_tbl.CounselorsName, Counselors_tbl.Counselor, Counselors_tbl.CounselorID, Counselors_tbl.EffectiveDate
HAVING (TanfActivity_tbl.EventDate BETWEEN @Beginning_EventDate AND @End_EventDate)
ORDER BY People_tbl.LastName, Counselors_tbl.EffectiveDate DESC