Simple games like Pelmanism (the matching game) are mainly a question of turn-taking. So you'd end up saying things like this:
'Go on. It's your turn.'
'Now it's my turn.'
'Whose turn is it?'
We can also use the word 'go' as a noun to replace 'turn':
'It's your go now.'
'No, it's not your go - it's my go!'
If she needs instructions you can say:
'Turn a card over' / 'Turn over a card'
'Which card are you going to turn over?'
When she turns over a card, you can say:
'It's a fish!' 'Now, can you remember where the other fish was?'
'Oh! Well done! That's a pair!'
'Ahh, never mind!'
'Try again.' 'Have another go'.
You're the winner!
I hope that's the kind of thing you were looking for - do ask if there's anything else you'd like to know.