Forcing the Language!

I am no expect at teaching and I am no child psychologist but so far we have been having some great result with the way Tullula is evolving with the French Language!
So I started to wonder if it was good or not to actually force it upon them was mentioned to me!

I have quite a few multi-lingual families around me. And the children that are in one language house holds really seem to take to their mother tongue so much more..I envy it, yet understand why!
I have one German couple, and naturally their little girl speaks a lot of German, sure she mixes both languages as well, and she even makes up her own words that are half German hand English, but being that when she is at home both her father and mother speak in German, she does too!

Then I know a French couple, their little one is only starting to talk, but its pretty clear that he favors French! Despite the fact that he too goes to day care a few days a weeks, he still is showing sings of talking more French!

Where did she get such long eye lashes from?

I must say, I find it adorable to see these little people taking their native language in Australia, it just adds  another dimension to the word cute!

That's when I was told that maybe I should just tell Tullula that i did not understand her when she spoke to me in English, in order to force he to speak to me in French!
I must say I did do it a little, especially when she would say "Good Night" I would make her say in in French, and she did! Then I would also make her repeat things in French when she wanted something, and she would do it when she wanted what ever it was bad enough!
But then there have been other times where she would just not want to, I know she understood what I wanted from her, but somehow she just did not want to do it!

Like tonight I said "Bonne Nuit" (good night in French) and that's one of the few things she actually was doing, repeating it in French to me...But lately she has not been, and I would just leave it at that and walk out of her room..Tonight I did not, I repeated myself, and waited for an answer...It eventually came...In English!
I told her to say it in French, and she just shrugged her shoulders, making it clear to me that she had no desire to do so!
So I left it at that...

I don't know, should I force it on her, at the risk of her hating French altogether because it was such a burden on her? I don't want to do that...Yet I am stepping on little stones here as reality is I have no idea how its done to raise a bilingual child!!!
And I think reality is there is no wrong or right way, as every child is different in their ability and willingness to do things!

I think for now I will leave it this way and just be happy that she still is understand EVERYTHING I say to her in French, and be happy to hear the few words that she does say in French and hope that this upcoming Europe trip will change the way she does use the language!
I hope, because I really long to hear her talk to me in my mother tongue someday!

Anyone got any ideas on the topic?