It will be fine for the Sims 3. I have a friend who plays it on a 4th gen Intel i5-4210u with the Intel HD 4400 graphics core on 1920x1080 resolution and I am pretty sure all of her settings were on high. A 7th Core i3-7100u with a more powerful Intel HD 620 graphics core should have no problems. Though, I would recommend you increase the RAM to 8GB. She was having periodic crashes when her laptop only had 4GB of RAM. Integrated graphics use some of the RAM installed in the laptop. The higher the resolution / higher graphic settings the more RAM the Intel HD 620 will need. No enough RAM can cause crashes.
The following short video demonstrates the Sims 4 on laptop with a 6th generation Core i3-6100u and Intel HD 520 graphics core. Only the base game is being tested at 1080p resolution with medium graphic settings. Since the Intel HD 620 is slightly more powerful you may get slightly better performance.
The thing about integrated graphics is that you should always install a 2nd stick of RAM. When there are two sticks of RAM instead of just one, the RAM is operating at dual channel mode (full speed) rather than single channel mode (half speed). When it comes to average daily tasks you should not notice much of a difference other than perhaps less disk caching; swapping data between RAM and the hard drive when Windows is running out of RAM. However, when it comes to playing games using integrated graphics the increase in performance can be between 10% to 20% depending on the game. Plus more RAM means lower risk of the laptop crashing (especially if there is only 4GB of RAM) so that you will not be loosing progress.