looks like the mother plant is just declining which normal ...as it dies of just trim away the dead parts and let the pup replace her...other pups may even appear ..if its cold where you live it might be best to bring the plant indoors into a brightly lit area

I agree. It doesn't look sick to me, just going through its natural cycle. Like most bromeliads, Guzmanias bloom only once, and the flowers don't last forever. Older leaves will turn brown and can be removed or trimmed. As it fades it will produce new plants (pups) which can be removed once they're about half the size of the mother plant, and potted. These will give you your next generation of bloom once they've matured.