Many of the Belgian records on familysearch are not fully indexed/name searchable.
Here is the direct link for the Antwerp area civil registration:
https://familysearch.org/search/collection/2138481Rather than searching click "Browse through 2,978,372 images". You are looking for "Antwerpen" (for the city) - you may need to check in these record for both French and Dutch spellings of place names. You will also need to learn some of the basic words (these records will be in Dutch, in other areas you will get French), e.g. numbers and for example "Geboorten" = births, "Tienjarige tafels " = 10 year indexes, but the civil records follow a fairly set format. There is a list of key words here:
https://familysearch.org/learn/wiki/en/Netherlands_Language_and_LanguagesThere is a yearly index at the back for each year, and sure enough, Madeline Eugenie Jean Emilie Stephany is listed in "Geboorten 1898" (3664 is the number of her birth record).
This is hopefully a direct link to her birth record:
http://www.rootschat.com/links/01960/There is a "Tienjarige tafels" image set for 1891-1900 which looks to be all marriages. There is only one Stephany marriage in it which is for Madeline's parents.
year 1896 act 1083
Huwelijken 1896 image 274
With luck another direct link:
http://www.rootschat.com/links/01961/ Emilius Maria Ferdinandus Stephany (latin form of his name, the "Maria" is not unusual as a baptismal name). My Dutch is not good (the vast majority of my Belgian lot original from French-speaking areas), but it seems they were both from Antwerp and that brother Emile de la Montagne was a witness to the marriage.
As well as the Huwelijken (marriages) you should check out the Huwelijksbijlagen (marriage supplements) where available. These are records basically of all the documentation the couple supplied to get married - can include extracts of birth records, death records for previous spouses or parents (to establish freedom to marry or who has the right to give consent to marry for a minor), checks that the husband hadn't ducked out of national service, etc. Emile and Alice's marriage supplements start here:
http://www.rootschat.com/links/01962/1) A document from a notary public confirming that Emile's widowed mother, resident in Saint Nicholas, Flandre, consented to the marriage
2) extract death record for Alice's mother
3) extract birth record for Alice
4) extract death record for Emile's father
5) extract birth record for Emile
6) Documentation of Emile's military service (national service).
You should go back and find the originals of the birth/death records as well. I hope I've given you a start, but I do encourage you to try and familiarise yourself with the record format. They are not too difficult to use and have a lot more information in them than English records!
Censuses/population registers were taken in Belgium but are seldom used for the simple reason that there are few indexes and searching a place like Antwerp by hand just isn't very feasible.