TD permits study but does not authorize employment. A proposed laboratory placement needs its own assessment, including duties, location and whether it is part of a course. Calling it training or making it unpaid does not settle the permission question.
Keep the dependent activity separate
The principal’s support relationship with scientists does not extend work authorization to the spouse. Obtain a description of any proposed placement before participation. If the spouse seeks an independent professional route, their own qualifications and engagement must be assessed.
Build a separate identity and relationship packet for each family member: passports, marriage record, birth records for children, and genuine name-change documents. A spouse who intends to work in the United States needs a classification of their own, assessed on their own citizenship, their own occupation and their own arrangement with an employer. Dependants admitted in TD status may live in the United States and may study, but the status carries no work authorization at any point and no permit converts it. If the spouse has a genuine job offer, review a separate immigration category and its timing rather than describing productive services as casual remote assistance.
Keep relocation, housing and the spouse's separate planning on their own lines, since none of them changes eligibility.