Baroque music did change quite a bit in just a few years... already towards the 1650 madrigals had gone from 4 voices performances down to three or two voices.
Monteverdi helped transition from polyphonic to monodic and concertato.
Girls the age of Pea would already know madrigals with soloist part and in the XVII century madrigals already had instrumental music accompanying the voices. Because England stayed behind in the evolution with madrigals... I am thinking Pea should sing solo madrigals with basso continuo using a lute, which was more common in Southern European Countries.