i think you should go ahead.

Gift of Money
Although it may seem too easy to give money since you don't have to spend time picking out something special, it is often the most appreciated gift of all. In addition to funeral expenses, there may be other things that the survivors need, particularly if the deceased was a primary or partial breadwinner in the family.

If you choose to give money, be as discreet as possible and avoid making an issue of it. This is not the time to embarrass anyone. Put your check or cash inside an envelope with the sympathy card and hand it to the person you want to receive it. If you're concerned that it won't be opened right away, you might mention that there is something extra inside.

..the husband of a woman passed we all collected about 1500$ and gave to her. She REALLY appreciated it. I think if you gave her 100$ instead of flowers to 'help with funeral expenses' that would be fine. Maybe give her a potted plant with it...something living.

at the viewing. Telling them they are going to need it because of all the expense. Discreetly, of course.

A couple of times when I knew the person or the family needed it. It sounds like it would be appropriate in the situation you described. You would just have to use your best judgment on how much to give, I guess.

I cried thankful tears over each. The generosity is traditional in many cultures and likely welcome in all.

... she was indeed very appreciative. Flowers and stands and sprays are nice, but when cash is what you truly need in a time of crisis... it means the world.

Thank you again everyone for the thoughtful comments!

along with my condolences, "Please use this as you see fit."

I wouldn't enclose cash without saying why. Adding a note saying you were enclosing a bit of cash to help them out during their bereavement would be appropriate. I would also think it should be of significance; not $5 or $10. That seems like a token. If it is truly to replace what you would spend on flowers, I think it would be very much appreciated.

Just my thoughts.

Edited to add: I just read some of the other responses. I am surprised this seems to be a fairly common practice. I really have never heard of it before, nor experienced it with losses in my own family. So there you go. Different traditions are what makes us all so unique.

The husband of the woman who used to cut my hair committed suicide a number of years ago. She had to keep working to support her children. About a month later, she cut my hair, about an $11 job, and I wrote a $50 tip into the check. I didn't say anything to her about it, but I imagine she got the idea.

And deeply appreciated, I bet.

The older generation sent cash when my Mom passed away and then the younger generation sent cash when my husband passed away. Both times, I used the money to buy food and supplies for out of town company.

When my husband passed away, I got money from several people. I didn't need it, but I appreciated the thought and sent thank you cards.

especially if you know they need it. As others have said, there is often a delay in getting funds for everyday things let alone funeral expenses. Cash would be very much appreciated. A friend of mine faced this when her husband died and she said she felt bad that people were offering her money. However, she needed money to make plans before any kind of insurance kicked in so I told her that people love her, want to do it and please TAKE IT! She seemed relieved to hear it.

funerals are expensive

You could write...'for the funeral' as people often contribute for a funeral and then they can do whatever they want with it.

I have also given grocery gift cards. I think people always appreciate a kind gesture.

My husband's best friend continued to check on me and quietly left grocery cards which were needed and greatly appreciated.