"I'm here for you if you need me"

I'd tell her yes then not do it.

Askher what you can do to help? Are you living near her? Is she ill? Figure out what you can do to help her. Financial? Child care? Cleaning? Cooking?

The truth is that while there isn't proof that prayer works directly, there IS proof of the placebo effect, and just the comfort of thinking that someone might be trying to do some imaginary thought work could be enough to help her legitimately take a turn for the better, physically, emotionally, and otherwise.

In that spirit, DO offer that comfort, for her sake. What have you got to lose? A single breath, uttering words like "I'll keep you in my thoughts. I hope all this gets better, soon," might just work.

I would lie and say I would pray for her,. Her comfort is more important than resisting her wish based on your disbelief.

While I don't believe in prayer per se, I do believe that sending positive thoughts cannot hurt.

I'd tell her what she wants to hear, just to make her feel better, the do what you can by conventional means.

I just say, "You'll be in my thoughts" instead of "I'm praying for you".

How about if I take you to (lunch, shopping, a movie...)
How about if I cook a few things for you?
How about if I run a few errands for you?
Etc.
SO much more helpful than talking to the non-existent!

I get that a lot I tell them my thoughts are with them. I know thoughts are as useless as prayers but it seems to make them feel better.

I tell people I will keep them in my heart's mind. That has to be as good as prayer, right?

Typically I tell people ill tip a beer to em.

I just say I'm sending positive thoughts.

I will not lie and say I'll pray, but that's me. I tell people I'll send good thoughts their way and keep them in mind. I think they are looking for some type of comfort and help, give her a hug and tell her she is always on your mind.
Just my two cents, for what it's worth.

I agree with everyone who said just tell her you will. Not doing so won't make any difference at all; her thinking that you will might help her feel happir.

Others have given good advice. I'll risk being off base to give a different opinion. I'll assume she doesn't know you are agnostic, because she asked you to pray for her. Furthermore, you aren't ready to tell her because she is having a tough time. I would tell her that I would pray for her, and perhaps say a little (disingenuous) prayer to satisfy my anxiety about lying. That's a placebo to make her feel better.

Then, do the things everyone else said, which might actually help her.

I have been in this situation before, and I usually just tell the person that I will. If it makes them feel better to think that I am praying for them, then so be it.

Similar things have been mentioned, but "I'll send good vibes" seems to work.

Just say ok... you wish her well, that’s the same thing and has the same outcome, so just say ok... And then just to lighten up the mood perhaps say something like, “how about that Darwin?”

I won't pray but I'll keep you in my thoughts. If there's anything I can personally do, just ask and I'll do whatever I can, in my power.

I agree with those who say offer tangible help. If there is nothing you can do, tell her she is in your thoughts and in your heart. I don't think it helps to lie.

You've already said it....... I want to help, but I don't believe in prayer.

tell her that you think about her all the time and that you are there fot her to talk to for emotionsl support.

Apparently she believes you are still religious? So I'd go with the flow and not cause more stress.

Yes most time its a plea for help ..Not a reglious one.