In BC, you don't need to use the same vaccine for each shot to be considered fully vaccinated. This person is expected to switch to a different COVID-19 vaccine for her second shot.
In the article if you look at the Twitter post shown, it shows a "Valid contraindications and deferrals to COVID-19 vaccination" which states the following:
"The following are NOT contraindications to COVID-19 vaccination: History of an anaphylactic reaction to a previous dose of mRNA or adenovirus vector vaccine. Such individuals may receive their 2nd dose using vaccine of the different type. History of an anaphylactic reaction to any component of one type of vaccine. Such individuals may receive vaccine of the different type."