I have shown the logos to other members of the foundation and it seems there is a preference for #38 than the variations of #39 and #40, which reminded them of a heart related charity in Australia. The comments were that they didn't really like the heart in the middle of #38 and that the font is too corporate. Can you soften it, maybe even something in more of a handwritten style could work?
That would not be a problem. But please note that in the current phase of the contest only the designer ranked at 1st place can submit changes. If you require changes from few different designers make sure you switch the ranking accordingly.