Answer: Unfortunately, the child does not have the right to enroll in your district under the McKinney-Vento Act. Your district does not meet the definition of school of origin, because the child never attended that school—it is not the school attended when permanently housed or the school in which last enrolled. 42 USC 11432(g)(3)(I). It’s also not a school that other children living where she is living are eligible to attend. 42 USC 11432(g)(3)(A).
If open enrollment or other transfer procedures are available for families to enroll from out of district, the family needs to have access to those. But there is no McKinney-Vento requirement to enroll the child in your kindergarten based on the siblings’ past attendance in your district. If there is no procedure available for the child to enroll in your district, then the child would need to enroll in the kindergarten classroom that other children living where she is living would be eligible to attend.