Can I book a flight ticket from the Uk if it's for a Thai person flying from Thialand to Uk?

My daughter-in-law has been granted her spouse visa to come to the Uk. Is it okay to book er ticket here in the Uk in order for her to travel from Bangkok to London? MY Son (her husband) will be flying out to Bangkok to meet her and bring her back to the Uk. So obviously he will have her e-ticket and will give it to her when he meets up with her in bangkok to bring her home here to the Uk.