Call CPS or say something?

I have a family friend with 3 kids, she is single parenting because one dad is in jail for 5 years and the other is a deadbeat. On numerous occasions my husband and i have seen things that make us question if we should call someone. The oldest kids have a bedroom that always reeks of urine to the point that I can't even walk past without gagging, my husband found a sharp bread knife in the two oldest kids bed, the kids do not all have proper car seats for their ages and sizes and the ones they do have aren't alyways used, recently she has taken and posted videos of herself while driving with the kids in the backseat and you can tell they aren't in car seats or buckled properly. If you were in our situations what would you do?

Edit: My husband is the oldest kids godfather and found the knife while he was putting the oldest down for a nap. Also we have given her money and help in the past but nothing ever changes. We only have so much time, energy and money to give. There are always excuses for why things aren't being done. Also this isn't about her friendship with usbeing more important than the kids. It's about her keeping the kids from my uusband If she found out it was is that called. He's the only consistent make figure in these kids lives.