This question raises many issues of California divorce law involving community property and child custody. On the one hand, the house seems to have been kept separate by keeping your spouse off the mortgage. On the other hand, funds were commingled to pay the mortgage, which would indicate co-ownership. If you also allowed your spouse to alter it, redecorate, or remodel, that would further indicate an intention to share ownership. Your custody battle could also influence who gets the house because the court favors stability for young children and, in some rare cases, the court may want the house to go to the parent who has primary custody. Of course, you may be overlooking other factors that could determine the outcome of your case.