4 weeks old kitten (HELP)

[ritagbap]

Hey guys,
4 weeks ago one of my grandma’s cats had a kitten (only one) but a couple of days later she just abandoned and stopped feeding her (the kitten is a girl) completely. After trying our best to get her interested in her baby again we decided to step in and start feeding her with kitten formula and we re doing everything by the book and she seems to be doing very well (she’s starting to play and develop a personality, weights 370g, seems overall happy). The thing is that 4 days ago it was the last time she pooped and Im kinda concerned. She used to do it once a day or once every 2 days (she’s never been this long without pooping). Ive been patient and tried to take more time to stimulate her but she doesnt seem interested in doing it.
Is this normal? Do cats start pooping less when they re older? Help please. Other than this she seems to be thriving and doesnt seem affected by not pooping (she’s playful and happy).
Thank you for your attention!

[jinksandchewie]

Please take her to the vet - 4 days is not good