Good attitude.  It takes many skills to play well and vibrato is only one of them and, by no means, most important.   However, try some vibrato even if it hardly works.  Just a little time now and then will help.  It will take some time. 

Besides, if you play mostly fast music you won't need vibrato at all 

I have been playing on and off for about 2.5 years now (have had regular lessons and playing regularly for about 1.5 years) .

Like Fiddlerman, I started to try vibrato from the very beginning; I could do finger and wrist vibrato then. However, like all of you have said and from what I have read it's advised not to start vibrato too soon so I decided to wait till our teacher started to teach my daughter so I could do it right (Chinese saying: "it takes three days to build up a bad habit and it takes three years to undo it).

Our teacher has a system for teaching vibrato. When she first started teaching my daughter (over six months ago) I was not too interested for some reasons.  Then when she started teaching me about a month ago, she went through the steps in a swift with me. I guessed since I am a visual learner and since I watched FM's video and observed closely how our teacher taught my daughter so I was in advantage of picking up vibrato. Now I am doing it right but I still need to practice it more until it becomes natural and automatic for me.  

From my own experience and my teacher's advice, to do vibrato, one will need to relax all joints involved, thumb has to be supporting the scroll yet not tightly hooked onto scroll to allow other joints to "swing" to make vibrato (not having the thumb hook tightly to the scroll is also helpful for shifting). The other thing is when you do vibrato, the root joint of your index no longer touching the neck of the violin, unless you are playing on open strings. From my own learning experience, the most helpful thing was when the teacher put her hands (fingers?) on my hand to show me what the right movements supposed to feel like for vibrato.

I agree with all the comments that to take advantages of the non vibrate time to focus on intonation, dynamics, expressions, phrasing, bow techniques, etc. you know when you are ready for vibrato like a child will roll over, sit up, crawl, pull up, free stand, take steps, walk, run, and climb when he/she is ready for the movements. So, take your time. You don't do vibrato does not mean you are not a good player. I have seen kids that don't do vibrato even when they were in Suzuki book 4 and 5, yet, they were fantastic players! Somewhere I read, "Vibrato for some it comes fast, for some it take times" so go with your own pace.