brazilian victoria 's secret angel underwent medical procedure and is still recovering in hospital .
she had been suffering ` constant headaches ' and had booked appointment two weeks ago , daily mail online told by a friend .
mother-of-two had appeared well as she spent time at coachella festival with celebrity friends including kylie jenner and gigi hadid .
procedure at ucla 's ronald reagan medical center was successful and aides said she is ` fine '
ambrosio , 34 , had posted on instagram yesterday about how much she was enjoying coachella saying : ` what a wonderful world . '