newfoundlands....when do they first come into season

[newfie owner]

hi,
   long time no post haha,how are you all? we were wondering when o newfies come into season?? molly is now 19 months old,would it be from 6 months old or is it nearer to her being 12 months old?

 also my lhasa apso bitch is late for coming into season and l wondered is she waiting for molly to come into season,as l read that bitches who are in the same house can come on heat around the same time

 have fun,hope to hear from someone soon hee hee

 debi and ste