best area for families? (Brussels)

H! My husband is up for a job in Brussels city center. We would be moving from the US. The position starts in July. I have never been to Brussels and would love any information available! If offered the job, he would be working in the center of the city, near CHU Saint-Pierre hospital. We have 2 young children under the age of 3, and we will not have a car. We'd need a 2 bedroom apartment in a safe area, of course. Preferably in walking distance to everything - grocery stores, parks, restaurants. If he can't walk to work, then it would need to be close to public transport. Does anyone have suggestions of areas to look? I have seen some affordable apartment options in the city center, but, of course, I have no idea if they are in "good" areas. I just need to feel comfortable pushing a stroller down the street. Thanks in advance!