I recommend you upgrade the RAM with at least another 4GB stick of RAM.
Several years ago a friend of mine was playing the Sims 3, but she complained that sometimes the game will crash which caused her to loose a lot of progress. Her laptop had integrated graphics. That meant Windows, the Sims 3 and the Intel HD 4400 in her laptop were all trying to use the same 4GB of RAM she had in her laptop. After installing a 4GB stick of RAM (total of 8GB) the Sims 3 was stable.