Howdy Modi: Know why did PM Modi apologise and congratulate Senator John Cornyn's wife

Prime Minister Narendra Modi apologised to Senator John Cornyn's wife as John was with PM Modi during the Howdy Modi event and his wife was alone on her birthday. After that PM Modi also congratulated Senator's wife via a video message.
On the other hand, Prime Minister Modi also extended invitation to the US President and his family to visit India, saying it will give a new height to the relations between the two countries.