Answer: The term “club sport” can mean different things in different places, so first, we need to clarify that club basketball is a school activity, and not a community league or otherwise not directly connected to school. If club basketball is not a school activity, the McKinney-Vento Act will not apply. However, assuming that club basketball is a school activity, then McKinney-Vento does apply. McKinney-Vento defines “enroll” to include participating in school activities, which includes academic, athletic, and other school activities. So McKinney-Vento students need to be able to participate. In addition, as you said, if this student cannot play basketball, it could be a barrier to her retention in school, since basketball is keeping the youth engaged and successful in school.
The McKinney-Vento Act does not specify how the barrier needs to be removed— it could be the DHS worker signing, which as you said, would probably be the best resolution. It also could be a judge’s order, or the student just signing for herself. McKinney-Vento requires elimination of the barrier, but the “how” is up to the school district and the situation.