I am a private practitioner and have a private clinic at home where I see patients. Is it okay for me to see a girl together with her mother if my wife is out of town or is this considered Yichud?
Although there are some Poskim who are lenient in this matter, practically, one is to be stringent unless the girl is between age five and 9, or you use another Yichud breaker option. Even if the girl is between age 5 and 9 this only helps during daytime hours, and at night prior to the normal time that people go to sleep. Those however who are lenient to not apply the prohibition of Yichud with a mother-daughter combination, have upon whom to rely.
Explanation: Simply speaking, a mother and daughter who are together are nonetheless prohibited from being alone with a man, unless the daughter is between ages five and nine or another Yichud breaker is applicable, such as that the clinic is open to the public to enter or see. Nonetheless, there are some Poskim of today who rule leniently in this matter on the basis that they are ashamed of each other and would not do anything in each other’s presence. Practically, one should not be lenient like this approach and should rather have other Yichud breakers available.
Sources: See Nitei Gavriel Yichud Poskim who are stringent: Setimas Hatalmud Uposkim; Pischeiy Teshuvah Y.D. 192:7; Devar Halacha 8 p. 72; Avnei Yashpei 6:59-3; Koveitz Mibeis Levi 4:49; Poskim who are lenient: Igros Moshe 2:15; E.H. 4:64; Nitei Gavriel 46:11 See in general regarding the concept of a Shomer breaking Yichud: Michaber 22:10; Kiddushin 81a; See regarding requiring the necessity to have two Shomrim at night: Rama Y.D. 192:4; Raavad; Devar Halacha 8:7; Nitei Gavriel 27:8; See regarding children breaking Yichud: Michaber E.H. 22:10; Tzemach Tzedek 39; Devar Halacha 4:1-3l; Nitei Gavriel 29:1-7;