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I think that maybe one thing you can do is write a letter out before you go and put it in your pocket. That way, it's with you already, already written, already to be presented to her, so all you have to do is hand it to her. Or, you can say right off the bat "I have something to say" so you won't be able to back out. If you have her email address, this is another option. You can email her letting her know you have something you need to talk about in your appointment. There's still a chance she'll check her email before her appointment, but if not at least you still may want to bring it up.

I think that here's the thing with suicidal thoughts: If your therapist has reason to believe you would go through with suicide, such as by mentioning you have a plan, she may have to tell in order to keep you safe. If you just mention you have suicidal thoughts without mentioning you have a plan, she may use her own discretion, but it is up to the individual therapist.

If you say you have been dealing with depression but don't say anything about wanting to kill yourself, she may be more likely to keep it confidential unless she has a reason to believe you'll be unsafe.

But, I recommend being honest with her, that's how you get the most help!