Adding more information based on today's article:
1) She had given birth in Seoul, South Korea.
2) Apparently, she came to know about the post-birth maternity services in South Korea after she appeared on the NTV programme "Another Sky" which aired last June. As such, she decided to head there for the childbirth in order to make use of those services.
3) Services reportedly include a ward which is like a hotel room, 24/7 support from the nursing staff and massages to rectify the pelvic bones which had expanded during pregnancy and childbirth.
4) The full package reportedly costs JPY 100,000 for two weeks.
Source: Sponichi Annex / Sanspo