Sorry, this reply is just going to be all over the place!!! Its really, really late now and I'm tired but can't sleep!!! You have been warned.
If English is your first language, then you have an advantage as much of English isn't new to you--its just...on vacation?
I would start trying to read/write a little in English several times everyday on the high-school level. Read short stories online, do word of the day, get a thesaurus--synonyms are your friend!!!
Look at 1-3 interesting pictures online with your DD each day and look at the pictures together. Describe them and talk about them. Look at animal pictures, pictures of outer space, pictures of cities, beaches, family, your old home with your family, other children etc...
Try to find some activity you can reliably do in English several times a week.
If she doesn't own a doll-house and a tea-set yet, this is the perfect age to introduce them as you can have English tea-parties and the dolls + their house is an excellent model of a typical home and gives you an opportunity. If you watch something on TV or DVD, like a movie. Talk about what happened 1st, 2nd, 3rd...last. Favorite parts, funny parts. Get some books in English.
I would take a look at Readingbear.com, progressivephonics.com and starfall.com. Reading bear will probably do the most for her vocabulary in the early stages sense they use simple words in sentences.
Play physical response games...things like Simon Says, Mother May I, and others so that she gets used to following direct commands in English. Get a couple of toys and put them in a basket. Let this be the "English Basket" when you play with a toy from this basket, you speak English!!!
Do you know any hand clapping games? Things like Tic Tac Toe, Patty-Cake, Rock-Paper-Scissors?
Now would be a fun time to introduce them as they are fun and novel ways to work on gross motor, rythym, cordination, language, ryhming and have fun at the same time.
Get one of those "First 1000 Words" book and keep it near at hand. Take 3 words a day and learn them, then play "I Spy" with your daughter.
I suggest looking into an E-Reader if getting phyiscal books is prohibitive, but first know that there are literally 1000's of books available online for free.
Is your daughter ready to read?
Look into The Reading Lesson, its available as a PDF and can be downloaded to a computer or printed. The first 40 pages of the book are free (2 chapters) it is very gentle but pretty thorough. The same company sells a vocabulary program, though it might be more appropriate after you finish the first ~10 lessons of the Reading Lesson.
Even if you read books in French then talk about them in English.
Study the pictures in English.
Describe pictures as colorful and vibrant, realistic or caricature, you might ask "does this animal look nice and tame or does he look wild and fierce?" to help your daughter learn the words tame vs wild.
Play the opposite game with dolls and stuffed animals.
"My doll is going
over the pillow so your doll is going to go
under the pillow"
"This dog is wild and loud!!! His brother is tame and quiet!!
"
That type of thing.
As you re-read books you've discussed you can advance the vocabulary you are using with your child. If last week, you talked about the "big dog behind the little dog", you might talk about how the "bigger dog walks behind the small dog." or how the lion which was described as "scary" last time might be "frightening" or "ferocious" when you read the book later.
Can you print off stories in black and white for her and make her some english books that way?
Maybe writing letters to her Anglophone family back home--you write and she dictate, will help fuel her interest in words and reading.
There are many educational videos on youtube, I would let her watch a couple of them ranging from PreK-3rd grade level and look up words for 1st, 2nd and 3rd grade vocabulary words, try and use 3 new words a week.
Make a word wall.
Perhaps you can use sticky notes to translate some of her french books into bilingual books. Get a 3x5 sticky note and write the English translation of each page, put the sticky notes in the French books so that you can read the same stories in English and French.
Make a list of words that you can use to describe various pictures in different books and put it on the back flap of the book and just subtly cross out the words that you have covered a few times, so you can gradually see a rough idea of any progress you make. Its a huge encouragement.
Does your DD like to make videos? Perhaps a private Youtube channel where she makes videos for her English speaking family by talking about her school, playing with puppets, singing a song etc...will also help her to feel more motivated to speak English??