The paperwork belongs to the place of death
Certification, the death certificate and any cremation permit come from the jurisdiction where the death happened — not from Texas, and not from where the family lives. That means the timelines and the waiting periods are that state’s, which may be shorter or longer than Texas’s 48 hours.
It also means the certified copies you will need for banks and insurers are ordered from that state’s registrar.
Cremate there, travel here
Transporting a body between states requires a licensed provider at both ends, an approved shipping container and airline cargo arrangements. It is expensive and slow. Cremating in the state where the death occurred and bringing the cremated remains to Texas removes almost all of that cost.
Cremated remains travel simply — see flying with cremated remains and shipping cremated remains. A memorial in Texas can then happen on the family’s own timetable.
Abroad, add the consulate
For a death overseas, the nearest US embassy or consulate issues a Consular Report of Death of a US Citizen Abroad, which is the document US institutions will want. Local law governs what may happen to the body, and some countries restrict cremation or require particular approvals.
Costs are borne by the family; the government does not pay for repatriation. Travel insurance sometimes does, and it is worth checking the policy of anyone who travelled.
What to do first
Establish which jurisdiction certified the death and get its contact details. Ask a local provider there for a direct cremation price. Order certified copies from that state. Then arrange transport of the remains. Doing it in that order avoids paying a Texas provider to coordinate something you can arrange directly.