Just got informed that I’ll be babysitting my new toddler tomorrow and the rest of the week. Any…

Just got informed that I’ll be babysitting my new toddler tomorrow and the rest of the week. Any tips on how to help all of them adjust? My daughter and the 3 year old I have now are used to playing together and stuff but the 2 year old that comes tomorrow doesn’t have ANY social skills, doesn’t like to share, and is a little more “wild” than my other two.. I want to keep all of them comfortable and help them get along and adjust but I’m not sure how it’s gonna go. The 2 year old is my SO’s niece so she’s used to me and my daughter a little bit but it’s still gonna be new to her.