Baby will only go to sleep when sucking my finger

Hello, my 3 month old daughter will generally only go to sleep when sucking mine or my husband's finger (she will also sleep in the babybjorn, pram occasionally, and also in the car but at home / in the evening obviously this isn't an option). I feel quite stressed, guilty & worried that we are stopping her from ever self-settling by continuing to get her to sleep in this way and by using sleep props but every time we try something else (shh-pat, spaced soothing etc) it doesn't work so we resort to letting her suck one of our fingers again. We have tried to get her to take dummys, very occasionally she will, but no real success. If anyone has experience of this and can offer any advice or stories of how things turned out it would be much appreciated. Thank you.