Your room is 'ta chambre', your sister's room is 'la chambre de ta soeur' in French.
"chambre de ma soeur"
Seven sisters are "sept soeurs" in French.
la chambre de ma soeur
'sisters forever' is 'sœurs pour toujours' in French.
"Mes deux soeurs" is how you say "my two sisters" in French.
Sister is "soeur", pronounced 'sir'.
my twin sisters is mes soeurs jumelles
"Utility room" in French is "buanderie".
Pas de soeurs
The cloak room or coat room is "le vestiaire" (masc.) in French.
You would say "je n'ai pas de soeurs" in French to express that you do not have sisters.
The French word for "Cindy's room" is "Cindy chambre".