Didn't need one with DD1, a calm child. DD2 was a different sort altogether - fussy, wriggly, on the go from morn to night, a nightmare in the car wriggling, straining, whingeing. I was happy to entertain and soothe most of the time but it was just impossible all the time, eg when driving to collect DD1 from school.
My mother suggested a dummy and I tried it despite having misgivings but it helped so much I never looked back. At last some longer stretches of sleep, as when not actually hungry she very quickly learned to find it in the night and pop it back in by herself and settle again.
When she got older (2 ish) I had a rule 'only in your bedroom' which worked well on a couple of levels as a) she didn't walk around with it all the time and b) sometimes she chose to go into her room and amuse herself for a while in bed with books or pottering. She seemed to need that calming-down, self soothing time.
Invaluable when ill, too - some children are just very sucky and a little bit fretful and it can help them to sleep a little better when poorly.
She gave it up rather later than some I must say - she loved her dummies so much she would sleep with one in her hand and one lodged under her nose, as well as the one in her mouth (aargh!) She's grown-up now and just as lovely as her non-dummied sister 
Try it and see if it helps, perhaps. And remember the 'only in your bedroom' thing when she's old enough to understand that.