私は現地でツアーに参加しましたが その時のガイドさんは 週末はバス乗り入れ禁止で手前の駐車場からシャトルバスで入ります。 このバスは許可申請しましたので乗り入れます。と。 事前に申請しないと乗り入れできないようでした。

The alley is very small and packed with people moving to both directions.

Like other markets they start early and I think with one hours travel from Taipei if u started at 8.30am you would still catch the famous food shops. Even if not open you can catch the scenery.

私は、公共交通(バス)わ使ったのでよく分かりません。そして、台北に帰る道が、渋滞で、23時位まで全然動かなかったので、ネットの情報「一泊を強く勧める」を信用して良かったと想いました。 回答になっていませんね。 ごめんなさい、

It is not advisable to bring an infant to Jiufen coz it is crowded with tourist. Stairs are steep too especially when u r carrying ur baby. No nursing station/room. There is no baby changing room on all their toilets

Get to Taipei train station first. Take the MRT. Then take the train heading for Reifun. Next take the bus from Reifun to jiufen. Because it is quite cheap, may be less than three hundred NT$. The MRT takes NT20 The train is less than NT100 The bus is cheap. It is sure to be a trip within your bargain if you don’t consider the taxi.

It would be really tough. It’s a hill with lots of steps and while not really steep it’s pretty crowded.

I am not a travel agent, just a tourist like you

by train would be ideal if you are from Taipei Main Station.

We took an umbrella stroller with us - a lightweight, easily foldable one - which worked fine in the old street (smooth pathway with no steps), and was useful for carrying shopping bags. But to get to the old street, we had to walk up 3 flights of stairs since our driver dropped us off the temple. Our two year old walked up the stairs and We carried the stroller up. I did see cars driving by the entrance of the old street so maybe you can ask driver to drop you off directly there? You may also want to bring a baby backpack carrier so you can alternate and for hiking.