I'm stuck with this recursion which doesn't work as I expect.

Where is my mistake?

#!/usr/bin/prolog

% Facts

mother( jeanne   , michel  ). % great-grandmother, grandfather
mother( genevieve, aubin   ). % grandmother, father
mother( irene    , alain   ). % great-grandmother, grandfather
mother( emilie   , colette ). % great-grandmother, grandmother
mother( colette  , muriel  ). % grandmother, mother
mother( muriel   , eve     ). % mother, daughter

father( joseph   , michel  ). % great-grandfather, grandfather
father( michel   , aubin   ). % grandfather, father
father( xxx      , alain   ). % great-grandfather, grandfather
father( marcel   , colette ). % great-grandfather, grandmother
father( alain    , muriel  ). % grandfather, mother
father( aubin    , eve     ). % father, daughter

% Rules

parent( Mother, Child ) :- mother( Mother, Child ).
parent( Father, Child ) :- father( Father, Child ).

ancestors( [Parent|Ancestors], Child ) :-
    parent( Parent, Child ),
    ancestors( Ancestors, Parent ).

% Queries

:-
    ancestors( Ancestor, eve ),
    format( 'Eve ancestors: ~w~n', Ancestor ).
% expected answer is [muriel, colette, alain, emilie, marcel, irene, xxx, aubin, michel, genevieve, joseph, jeanne]

EDIT here is the final solution, thank you all.

#!/usr/bin/prolog

/*##- Facts -##*/

mother( jeanne   , michel   ).
mother( genevieve, sylvie   ).
mother( genevieve, brigitte ).
mother( genevieve, aubin    ).
mother( irène    , alain    ).
mother( émilie   , colette  ).
mother( colette  , muriel   ).
mother( colette  , olivier  ).
mother( colette  , audrey   ).
mother( colette  , stéphane ).
mother( muriel   , eve      ).

father( joseph  , michel   ).
father( michel  , sylvie   ).
father( michel  , brigitte ).
father( michel  , aubin    ).
father( séraphin, alain    ).
father( marcel  , colette  ).
father( alain   , muriel   ).
father( alain   , olivier  ).
father( yves    , audrey   ).
father( yves    , stéphane ).
father( aubin   , eve      ).

/*##- Rules -##*/

parent( Mother, Child ) :- mother( Mother, Child ).
parent( Father, Child ) :- father( Father, Child ).

ancestor( Parent, Child ) :- parent( Parent, Child ).
ancestor( GrandParent, Child ) :-
    parent( GrandParent, Parent ),
    ancestor( Parent, Child ).

grandMothers( GrandMother, Child ) :-
    mother( GrandMother, FatherOrMother ),
    parent( FatherOrMother, Child ).

grandsFathers( GrandsFather, Child ) :-
    father( GrandsFather, FatherOrMother ),
    parent( FatherOrMother, Child ).

parents( Mother, Father, Child ) :-
    father( Father, Child ),
    mother( Mother, Child ).

strictSiblings( SisterOrBrother, Child ) :-
    parents( Mother, Father, Child ),
    parents( Mother, Father, SisterOrBrother ),
    SisterOrBrother \= Child.

siblings( SisterOrBrother, Child ) :-
    mother( Mother, Child ), mother( Mother, SisterOrBrother ), SisterOrBrother \= Child ;
    father( Father, Child ), father( Father, SisterOrBrother ), SisterOrBrother \= Child .

/*##- Queries -##*/

theMother :-
    mother( Mother, eve ),
    format( 'Ève\'s mother: ~w~n', [Mother] ).
theFather :-
    father( Father, eve ),
    format( 'Ève\'s father: ~w~n', [Father] ).
theParents :-
    setof( MotherOrFather, parent( MotherOrFather, eve ), MotherAndFather ),
    format( 'Ève\'s parents: ~w~n', [MotherAndFather] ).
theGrandMothers :-
    setof( GrandMother, grandMothers( GrandMother , eve ), GrandMothers ),
    format( 'Ève\'s grand-mothers: ~w~n', [GrandMothers] ).
theGrandFathers :-
    setof( GrandsFather, grandsFathers( GrandsFather , eve ), GrandsPères ),
    format( 'Ève\'s grand-fathers: ~w~n', [GrandsPères] ).
lesEnfants :-
    setof( Child, parents( genevieve, michel, Child ), Children ),
    format( 'Geneviève and Michel children: ~w~n', [Children] ).
theTwoParents :-
    parents( Mother, Father, eve ),
    format( 'Ève\'s mother and father: ~w, ~w~n', [Mother, Father] ).
theStrictSiblings :-
    setof( SisterOrBrother, strictSiblings( SisterOrBrother, muriel ), SistersAndBrothers ),
    format( 'Muriel\'s strict siblings: ~w~n', [SistersAndBrothers] ).
theSiblings :-
    setof( SisterOrBrother, siblings( SisterOrBrother, muriel ), SistersAndBrothers ),
    format( 'Muriel\'s siblings: ~w~n', [SistersAndBrothers] ).
theAncestors :-
    setof( Ancestor, ancestor( Ancestor, eve ), Ancestors ),
    format( 'Ève\'s ancestors: ~w~n', [Ancestors] ).
:-
    theMother,
    theFather,
    theParents,
    theGrandMothers,
    theGrandFathers,
    lesEnfants,
    theTwoParents,
    theStrictSiblings,
    theSiblings,
    theAncestors,
    halt( 0 ).

And the output is:

Ève's mother: muriel
Ève's father: aubin
Ève's parents: [aubin,muriel]
Ève's grand-mothers: [colette,genevieve]
Ève's grand-fathers: [alain,michel]
Geneviève and Michel children: [aubin,brigitte,sylvie]
Ève's mother and father: muriel, aubin
Muriel's strict siblings: [olivier]
Muriel's siblings: [audrey,olivier,stéphane]
Ève's ancestors: [alain,aubin,colette,genevieve,irène,jeanne,joseph,marcel,michel,muriel,séraphin,émilie]