Pheu Thai PM candidate Paetongtarn Shinawatra, her sister, Pintongta, their husbands and friends visited the shrine together on Sunday morning.
After praying at the shrine, they moved on to pray at the Temple of the Emerald Buddha and also visited the Prasat Phra Thep Bidon throne hall inside the temple compound to pay respect to the statues of previous kings.
Paetongtarn shared photos of her group on Facebook, saying she prayed to sacred objects, Budda images and ancient kings ahead of her 37th birthday on Monday.
She and her sister also prayed for their father’s safe return to Thailand.
On Saturday, Paetongtarn said her father would land at the Don Mueang International Airport at 9am on Tuesday.
Authorities have started preparing to receive the fugitive former premier who is a convicted felon. Thaksin has been living in self-imposed exile since he was ousted in a coup in 2006 , except for a brief visit in 2008. He has been sentenced to 12 years in jail in four cases, but one case with a two-year jail term has expired.