How to add dynamically a form or forms to django ModelAdmin formset before rendering

Using Django The Admin
1

I’ve two models Person with many to many on itself and Relationship as a through for that field.
How to add additional form/forms to formset of that many-to-many relation dynamically?

models.py:

class Person(models.Model):

first_name = models.CharField(_('first name'), max_length=30, blank=True, null=True)
last_name = models.CharField(_('last name'), max_length=30, blank=True, null=True)
related_to_me = models.ManyToManyField(
    'self', null=True, blank=True, related_name='me_related_to', symmetrical=False, through=Relationship)

class Relationship(models.Model):

class TypeChices(models.TextChoices):
   PARENT = 'PA', _('is my Parent')
    SPOUSE = 'SP', _('is my Spouse')
person = models.ForeignKey('Person', on_delete=models.CASCADE, related_name='related_person')
related_person = models.ForeignKey('Person', on_delete=models.CASCADE, related_name='person')
relation_type = models.CharField(max_length=2, choices=TypeChices, default=TypeChices.PARENT)

admin.py

class RelationshipInline(admin.TabularInline):

model = Relationship
extra = 1
fk_name = ‘person’

@admin.register(Person)
class PersonAdmin(admin.ModelAdmin):

inlines = [RelationshipInline]

In the admin site i can see all person spouses or parents, but I want to add children as well. How to prepopulate the corresponding formset with the data?