Nanny question

so I didn't know where else to post this question but I figured this would be the best bet! I am a Nanny for two little girls both of which have special needs, and they have a family member moving into their house who has two more little girls (they do not have special needs besides basic asthma care) they are asking me how much I would like my pay to go up per week. I am currently getting paid 200 a week for 2 children so what do you guys think is a reasonable addition for 2 more children?