I have to hold DD's dummy in til she's settled. Unless she's actually spitting it out.
She prefers the cherry ones, but the cheapest possible, coz the teat is softer. I have similar ones with a harder teat & she hates them. DS was the same. He had one for 4 months, BF for 23 months.
DD1 prefered the flat tip ones. Might give them a go actually. She might be able to hold onto them better...